Acer Nitro 5 AN515-45 Idle Temps are higher after a power cycle?

OK, so to provide a little background, I'm running a Acer Nitro 5 AN515-45 with a Ryzen 7 5800H (and RTX 3070), and I initially wasn't happy with the temps/fan noise which were at 55°C+ (with fans at 2000RPM+), so after some digging (this video specifically: https://youtu.be/muYHGjSS7Ls), I used the registry editor to enable the 'Processor Performance Boost Mode' option in the control panel, which I used to disable processor boosting on my 'balance [acer optimised] power plan'. This worked surprisingly well, My temperatures when being lightly used (browsing, using word/powerpoint etc.) would drop to 40-45°C, with the fans rarely going past 1500RPM, and occasionally turning off altogether if left at idle (dropping blow 39°C), without any use (such as browsing the internet). The only time It'd spike was if i opened a game launcher or opened/refreshed a load of chrome tabs at once, where the fans may spin up, then they would quickly wind back down. Whenever i'd run an actual game, i could run it without the boost for 57-80°C in games that'd normally push 90-92°C (unless it began effecting performance, then i'd switch to [high-performance] preset with boost on).

This is where we jump to about a week ago.

After a turn off/turn on, the temps suddenly went up, with 50-55°C being the new usual temps with fans speeds of 1800-2200RPM which is annoying to say the least, with the high-performance power plan (with the boost enabled) pushing it up to 60°C (when before it'd be from 40 to 50). The fans also keep ramping up and down between those two speeds which make it 1000 times worse. Before, the fans would only occasionally ramp up to only 1800RPM if i opened a couple of things at once or switched between a couple of tabs really quickly, and now that seems to be the lowest it'd drop to at all, with ANY kind of light use pushing the fans up to 2200RPM. Performance at gaming seems to be fine, but I'm kinda annoyed how something has changed, hardware or software-wise that's suddenly made the fan-noise push past 'barely noticeable' to 'jumping between 1800 and 2000 RPM every other minute'.

I gave the laptop a dust clean, even removing the fans to get inside the air-channels to get any build-up out, to no avail. I double checked the background processes to make sure there was nothing suspect running in the background, but it seemed fine. even closing all the startup apps (GOG, Steam, discord), didn't seem to help at all, the temps just sat at 55 at idle :(

If anyone has any ideas on helping me reign in these temps, I'd be highly appreciative. I was planning on performing a repaste at some point but I've only had this laptop for around a year or less, so i was hoping to only have to do that if there was some kind of serious performance drop. Also, whilst I can't be sure, I can only speculate that maybe the voltages to the CPU has changed, resulting in the higher temps? or maybe the thermal compound managed to crust-up reducing the conducution between the heatsink and processor? I have no clue, but if anyone has some advice, I'd be highly appreciative.

[Edited the thread to add model name]