Cursor not changing to correct shapes

This is doing my head in now. This has been happening to me randomly ever since buying a Mac last year. My cursor decides to not change to the correct pointer and either stays as a arrow no matter what i do, or it might flicker to the correct shape for a split second then back to an arrow, alternatively it might just start using seemingly random pointers leaving me thinking things like "I swear that open hand cursor wasn't used yesterday when i hover over a folder"

Ive just put up with it because it corrects itself randomly too. Chances are, if i restart my computer now, it will be fixed.

But I've just spent the best part of 30 minutes trying to fix a web design issue on my site, thinking the cursor wasn't coded right over a button until it dawned on me "I bet this is my stupid Mac with that stupid cursor bug" - and sure enough, I played around other areas and the cursor was wrong everywhere - so yes, i now want to get this fixed. This is with my iMac 2017 by the way.

I'm pretty sure a while ago I did a thing where i delete a file and it recreates it again several months ago that someone recommended but I'm happy to try any steps that anyone throws at me. Just bare in mind, that restarting will probably fix it.... until it breaks again.

This comes after a day of my keyboard and mouse losing bluetooth connection every 30 seconds, and my new Macbook deciding to just not play sound until i restart it (for the fourth time since buying it 2 months ago) - I am getting so fed up with these annoying bugs in all their sickeningly expensive products.

Rant over.. help please :-)