I've been trying to fix that it's been a few days right now, but it seems this bug just "doesn't want to get fixed".
I've looked into it quite a lot, and it seems that Redux cannot detect state changes when you change the value of the state directly.
Instead, you should return a new object with a different reference, and not just a new object with the same values. The REFERENCE to the object must be different.
I've tried returning the new value directly, changing the values directly, returning a new object, returning a new object created with the immer produce function, and it still doesn't work.
If you want to try and fix it, here are some resources that might help:
https://redux-toolkit.js.org/introduction/getting-started
https://immerjs.github.io/immer/
I'm pretty sure I'm just using Redux / Immer wrong, and this is causing the bug (of course, the source of 99% of the bugs come from people using the technology wrong), but after trying for so long, I've decided to just focus on other parts of the project, and then come back to this part in a few days when my mind is more clear again.
So, if you feel like putting your react / redux skills to good use, fell to take that task :)