I often need to copy size values from one box to another, but when I copy/paste number in the W-field I get the entire shape in the viewport instead. How can I prevent this and what do everyone else do?
Wow, very nice -- it works! Didn't think of that combination. Everything else (mostly) in Inkskapes MacOS-version works with cmd-key. Guess I may report it in Gitlab ...
I often need to copy size values from one box to another, but when I copy/paste number in the W-field I get the entire shape in the viewport instead.

How can I prevent this and what do everyone else do?
I don't (have never) encounter(ed) this (1.3 windows 11 and 1.4 lubuntu) :
1. Select an object
2 Directly select the height in H : field, copy it
3 Directly select the width in V : field, paste
4. Hit enter or tab key : the new value is applied
Sounds to me like you should reset inkscape preferences...
Thanks @David248
Attempts resetting prefs anytime when encountering anomalies – meaning quite often. And like now with no result.
I can conclude, that the weird behavior is not Inkscape by design.
Cmd-c an v don't work in the transformation panel either, yet RMD works fine.
In the topbar fields RMD makes no sence though ...
Kind regards, Raaskot
Did you try ctrl+c and ctrl+v in input fields?
https://gitlab.com/inkscape/inbox/-/issues/5917
Wow, very nice -- it works!
Didn't think of that combination. Everything else (mostly) in Inkskapes MacOS-version works with cmd-key. Guess I may report it in Gitlab ...
Thanks @Aero!