Text input&cursor movement lags by approx. 1s + no cursor blink

Issue type

UI bug (incorrect info or interface appearance)

Bug description

No response

Steps to reproduce

1. insert any text-only item (lyrics, chord symbols, staff/system text, expression, tempo, rehearsal mark)
2. (if needed) double leftclick to access textbox editing
3. write anything (avoiding spaces in the case of lyrics & chord symbols)

You (if your computer has the same generalised lag issues with MS4 that mine has, and I've been told that's rare even on machines that are lower spec than mine) will find that single characters appear after about 1s; typing several characters in a row leads to the lag stacking up more-than-proportionally up to the point of the program not responding; navigating with left and right arrows has the same effects; and the vertical line cursor doesn't ever blink (making it difficult to tell when a freeze is happening)

Screenshots/Screen recordings

No response

MuseScore Version

MuseScore version (64-bit): 4.2.0-233521124, revision: github-musescore-musescore-eb8d33c

Regression

I don't know

Operating system

Windows 10 home x64

Additional context

Re: regression status: The cursor doesn't blink in MS3.6.2 either, and there is some lag, but it is 1/4 of the lag found in MS4 and, unlike in MS4, it doesn't stack and cause freezes

Windows 10 home x64, AMD A8-7410 APU with AMD Radeon R5 Graphics
Processor: APU AMD Quad-Core A8-7410 (2,2 GHz, up to 2,5 GHz, 2 MB cache)
8 GB of SDRAM DDR3L-1600 (2 x 4 GB)
The disk is an aftermarket SSD.
NOTE:

• CPU use for Musescore rarely gets above 15% even in this and other laggy situations (and total CPU use rarely gets above 25%), despite the very low power of my cpu;
• RAM use sits between 20 and 30%, and while with Chrome open and a bunch of active tabs the total can reach 80%, the issue presents itself to an indistinguishable extent even when Musescore is the only program open;
• disk usage sits at around 0,5% even in laggy events, with some of them spiking to 1,5%.
  Thus, I struggle to identify the bottleneck.
  This isn't a playback issue, but just in case, I'm using MS basic.