Using Fedora 33 with MATE desktop...

I'm working with the developer of a very handy RPN calculator app called rpCalc to figure out why it doesn't work for my regular user 'doc' but works perfectly for a newly created user 'test'. The developer strongly suspects a Qt5 setting. We have narrowed our search to my local environment:

$ env | grep QT
QT_IM_MODULE=xim
QT_AUTO_SCREEN_SCALE_FACTOR=0
QT_SCALE_FACTOR=2

The developer believes the first (set to =xim) is causing rpCalc not to function at all, and that the next two cause the font sizes on the calculator buttons  to be oversize.

I'm looking for one or more config files -- probably in my home directory -- that set these variables. Talk about looking for a needle in a haystack.

Is there a cat | grep command (or equiv) that can recursively look for "QT" in all files in my home directory -- including hidden files? It would have to be able to output the full path to any files in which "QT" is found. Unfortunately cat does not support recursive searches.

--Doc Savage
    Fairview Heights, IL