Item previews endlessly loading.

There isnt a fix for that as far as I know. If you really want to "fix" it you can restart the server and game but you will still occasionally get that issue.

This seems to be happening a lot more in 1.6.0 than it did in 1.5. Every time I launch the game it has to regenerate all of the icons.

Don't mark my words but I've always had this bug. No matter if Sp-Tarkov or original Tarkov, in the meantime I've come to terms with it. Always after 2-3 raids and only a restart helps briefly before it starts again. Sometimes even in middle of a raid.