It has been recently found that this is likely an intentional feature, as I found a switch to enable the clear hotbar function in the settings.
It would've been great if it was enabled by default, to avoid issues with people like me thinking it was bugged.
Please mark this issue as resolved/intentional game design.
I can't believe this bugged mojang screen thing has come back, really annoying.
I am experiencing a similar issue, where my skin on my profile doesn't load.
Happens in all gamemodes as far as I can tell. Crashed multiple times after updating to 1.16.1, but all the times was when I was picking up a block in my inventory (on creative mode).
Original poster of this issue here.
I have long since given up changing the scaling and got used to using -2 scaling, but upon testing, I can confirm the issue is still present.