The 5090 could be released in 6 months, forget about the 40 series.
Add at least an NVMe for installing Windows and software programs. Do not use mechanical hard drive for Windows.
The B series board might not be good enough for the Ryzen 10,000 series, but 7800x3D is good, but playing at 1440p it's going to use more GPU than CPU, but 7800x3D is still exellent.
I do not have data service to be able to run a hotspot.
Why would something choose Telegram as a private alternative over Whatsapp? Can you message someone on Telegram who is not a contact? How do you you get around Felegram saving info and messages on their servers? XMPP would be a better choice with OMEMO.
I am considering changing from GrapheneOS to CalyxOS. I have never tried CalyxOS, I've used GrapheneOS on 3 phones.
I don't install any apps that are not from F-Droid.
Blind fans don't realize this, but it is possible to implement so much security in software that people can't use it due to too many repeated roadvlocks in trying to use everyday. Is it possible to implement too much privacy?
I will add on top of all the other recommendations, in F-Droid settings, turn off all anti-features. If after doing that, an app you are looking for is not available, check what anti-feature it has for why it's not listed.
I suggest RiseupVPN.
I face value from your description, I find it difficult to say if a program screwed up your system or if one program is conflicting wifh syatem swttings.
Apart from making sure all drivers and software is updated, uninstalling one program at a time to test for conflict, I would be inclined to erase drive and reinstall OS.
Due to playing game seems to make it run fine makes me think it's not a hardware failure, or games don't push the hardware in way to trigger what is beginning to fail.
I higher power supply would be recommended.
If you don't have an AMD 600 series motherboard, buy a X870 board and it will work with any Ryzen you buy.
The RAM might be able to go down to 6000 for the same performance.
I don't view using a FOSS frontend equating to logging into an account on a server running proprietary code. Using NewPipe is one thing, but if it was possible,, using NewPipe o login to Google account is another.
For example I refuse to use Proton VPN, I use Riseup VPN because the server for Riseup is open source.
In my own opinion, I believe Protonmail not publishing email server source code and publishing Protonmail app source code is stopping it from having a massively larger popularity.
OpenBSD is proof that security can be achieved through engineering open source code that is standards or protocol compliant and not by depending on proprietary code.
Which proves my point. Proton won't publish their server source code, so I don't have blind trust in any Proton service, including Protonmail.
For Proton Wallet, there are free/libre wallet alternatives without anti features.
I would suggest a X670E Aorus Master if you have the cash, otherwise X670 Aorus Elite AX. I can't justify the price of MPG X670E Carbon.