My guess - your Tk widgets are based on some references to scalar, which are no more used for database access.

to be less vague, let us say, database read code does something like this:

$obj->{_record} = {company=>'fkjfkdjfd',firstname=>'vmk'};
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or may be very differently, but similar in spirit; so there will be are another scalars.

To say, to access those, you use same formulae $self->{_record}->{company} but actual scalar is another.

You must understand that -textvariable=>\....... does not recalculates reference each time, it takes scalar reference which is lost by your further code.

just a guess

Best regards,
Courage, the Cowardly Dog