I don't have your platform to test on, but it sounds like a common focus issue. Try clicking the entry with the mouse first, before typing, or do this: 
$ent->focus;
MainLoop;

[download]
Only one widget can have keyboard focus at a time, often you will see a binding like this, to ensure an entry or text widget always gets keyboard focus: 
$mw->bind( '<Any-Enter>' => sub { $ent->Tk::focus } );

[download]
that will ensure that if your mouse wanders off of the app, the entry will regain focus when the mouse re-enters the mainwindow.
I'm not really a human, but I play one on earth Remember How Lucky You Are

In reply to Re: It seems that Tk has an error in some version by zentara
in thread It seems that Tk has an error in some version by llancet

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