(macOS) Qt Creator and Qt Design Studio – QML designer freezes or takes a long time to process basic operations

[SpookDome]

I've been trying to fix this problem for a week now, but to no avail.

Right now I want to start learning how to use QML instead of QtWidgets, but I can't even begin properly because no matter what I try, QML designer in both Qt Creator (enabled through plugins) and Qt Design Studio just freeze up all the time.
In my case, it works like this (manually timed):

Want to open a newly created empty 1920x1080 window in the designer? Wait 15 seconds.
Want to resize it? Wait 20 seconds after changing each axis.
Want to save it? Wait 3 minutes.
Want to add a label? Literally wait 7 minutes of "Qt Design Studio (Not Responding)" until it finally unfreezes.
Want to also add a button? After 20 minutes of waiting and fans spinning at full speed I simply gave up.

It's completely unusable - I can't use any GUI tools for designing QML's. I can still script them manually, but at this rate I might just stick to QtWidgets and Qt Designer, both of which work perfectly fine.

My specs are:

Model: MacBook Air 2020 (Intel)
OS: macOS Monterey (12.4)
CPU: 1,1 GHz Quad-Core Intel Core i5 (Turbo Boost – 3,5 GHz)
GPU: Intel Iris Plus Graphics 1536 MB
RAM: 16 GB 3733 MHz LPDDR4X

Qt: 6.3.1
Qt Creator: 8.0.0
Qt Design Studio: 3.5.0

Xcode and Xcode Command Line tools are both installed. Reinstallation of Qt didn't help, and neither did creating a brand new macOS partition and doing a fresh install of Qt on it. Except enabling QML Designer in Qt Creator in the plugins section, all settings are set to default. Other software such as Autodesk Maya and Adobe Photoshop CC have no performance issues on my machine. Opening Activity Monitor whenever the QML designer was not responding showed both high CPU and disk (read) usage.