Just for the record, the correct certificates for Perlmonks (all servers) are issued by Sectigo. I think somebody (your employer?) installed an SSL-decrypting endpoint like a transparent proxy and forgot to install the wildcard certificate of it into your Chrome browser.

openssl s_client -showcerts -servername 216.92.34.251 -connect css.per
+lmonks.org:443 </dev/null
[download]

openssl s_client -showcerts -servername 66.39.54.27 -connect css.perlm
+onks.org:443 </dev/null
[download]

CONNECTED(00000003)
depth=2 C = US, ST = New Jersey, L = Jersey City, O = The USERTRUST Ne
+twork, CN = USERTrust RSA Certification Authority
verify return:1
depth=1 C = GB, ST = Greater Manchester, L = Salford, O = Sectigo Limi
+ted, CN = Sectigo RSA Domain Validation Secure Server CA
verify return:1
depth=0 
verify return:1
---
Certificate chain
 0 s:
   i:C = GB, ST = Greater Manchester, L = Salford, O = Sectigo Limited
+, CN = Sectigo RSA Domain Validation Secure Server CA
   a:PKEY: rsaEncryption, 2048 (bit); sigalg: RSA-SHA256
   v:NotBefore: Sep 19 00:00:00 2023 GMT; NotAfter: Oct 19 23:59:59 20
+24 GMT
-----BEGIN CERTIFICATE-----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      
+                                                                     
+                                                  
l3r8IgdDMLhZAXAvzecWAiEAkMYKgnrqr9GBC8O908b6SImEfu3kg06Du7ktvUWH      
+                                                                     
+                                                  
rxswga0GA1UdEQEB/wSBojCBn4IRY3NzLnBlcmxtb25rcy5jb22CEWNzcy5wZXJs      
+                                                                     
+                                                  
bW9ua3MubmV0ghFjc3MucGVybG1vbmtzLm9yZ4INcGVybG1vbmtzLmNvbYINcGVy      
+                                                                     
+                                                  
bG1vbmtzLm5ldIINcGVybG1vbmtzLm9yZ4IRd3d3LnBlcmxtb25rcy5jb22CEXd3      
+                                                                     
+                                                  
dy5wZXJsbW9ua3MubmV0ghF3d3cucGVybG1vbmtzLm9yZzANBgkqhkiG9w0BAQsF      
+                                                                     
+                                                  
AAOCAQEAO1PWPoEwyH9sPcps5rzX0qxfLjEb1eM3MyEwBh+RW42plZ1D7yZRhZgj      
+                                                                     
+                                                  
VuczaExbAYs//8Rc8PUxfYd+MOA5HrIzFNzbT9Xjtf86LgDVCYUdnC4r3ar1Kpxv      
+                                                                     
+                                                  
BycULlFBU2GZkiRtjKQ+aMLcX3bHi1RcCz7coAsR0wbriDip8sMoxW0BrcE/6NH5      
+                                                                     
+                                                  
ySGb/0MkTLdER6nFShjAnfJ/qzCE+l86anNbOm4mj3EsVQLJDjNiiBPJI2G+KSqH      
+                                                                     
+                                                  
kYYWcvx4Nbciu+NWubmiTkUYUK8TUZN8JzhPXIhfsAsJBhNFYsh9Jt/exI58UzR1      
+                                                                     
+                                                  
j8vvSCvXXO283Ag4+N2a87PKLIgxPw==                                      
+                                                                     
+                                                  
-----END CERTIFICATE-----                                             
+                                                                     
+                                                  
 1 s:C = GB, ST = Greater Manchester, L = Salford, O = Sectigo Limited
+, CN = Sectigo RSA Domain Validation Secure Server CA                
+                                                  
   i:C = US, ST = New Jersey, L = Jersey City, O = The USERTRUST Netwo
+rk, CN = USERTrust RSA Certification Authority                       
+                                                  
   a:PKEY: rsaEncryption, 2048 (bit); sigalg: RSA-SHA384              
+                                                                     
+                                                  
   v:NotBefore: Nov  2 00:00:00 2018 GMT; NotAfter: Dec 31 23:59:59 20
+30 GMT                                                               
+                                                  
-----BEGIN CERTIFICATE-----                                           
+                                                                     
+                                                  
MIIGEzCCA/ugAwIBAgIQfVtRJrR2uhHbdBYLvFMNpzANBgkqhkiG9w0BAQwFADCB      
+                                                                     
+                                                  
iDELMAkGA1UEBhMCVVMxEzARBgNVBAgTCk5ldyBKZXJzZXkxFDASBgNVBAcTC0pl      
+                                                                     
+                                                  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-----END CERTIFICATE-----
---
Server certificate
subject=
issuer=C = GB, ST = Greater Manchester, L = Salford, O = Sectigo Limit
+ed, CN = Sectigo RSA Domain Validation Secure Server CA
---
No client certificate CA names sent
Peer signing digest: SHA256
Peer signature type: RSA-PSS
Server Temp Key: X25519, 253 bits
---
SSL handshake has read 3822 bytes and written 399 bytes
Verification: OK
---
New, TLSv1.3, Cipher is TLS_AES_256_GCM_SHA384
Server public key is 2048 bit
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
Early data was not sent
Verify return code: 0 (ok)
---
DONE
[download]

The common name (CN) on the certificate is blank which is frankly very weird. SSLlabs gives it a pass but you can see from the report that the common name is blank. It would not be surprising if this resulted in some problems here and there.

Update: in Corion's post the openssl trace inlcudes this:

Certificate chain
 0 s:
   i:C = GB, ST = Greater Manchester, L = Salford, O = Sectigo Limited
+, CN = Sectigo RSA Domain Validation Secure Server CA
[download]

which explicitly confirms that the Subject (the line containing "s:") of the server certificate is entirely blank.

Have you or your employer engaged the services of https://gttb.com/?