Magic Mouse 1&2 incredibly slow but other bluetooth devices okay

I have a 2019 15" i9 MacBook Pro with 32gb memory.

Since late last year I began to notice my Magic Mouse 1 was sometimes stubborn, it would be very slow and not always responsive.

Things began to get worse over the months and it would get to a point where the mouse just wouldn't move at all unless it was reset and stuck practically on top of the MacBook.

I tried resetting my bluetooth module, deleting the bluetooth prefs files, renaming the device, repairing the device, unplugging usb c devices, trying it without my old school 30" cinema display plugged in but still it would happen. At best it always felt like heavy cpu usage triggered it but I sort of debunked that by keeping Intel Power Gadget open, my core average sits at around 3.2-3.6ghz when the "lag" happens, also my trackpad would resume perfectly fine.

Eventually I upgraded from Mojave to Monterey hoping for a potential software fix but still no luck, so instead of upgrading I took a file backup and reinstalled Mac OS Monterey completely fresh, still however it was no better.

Last month I caved in and decided it must be the mouse, I bought a brand new space grey Magic Mouse 2 and things were "sort of okay" but within a week it was back. I even tried swapping the desk surface but that just made it worse. I have checked the sensor area and cleaned it with microfibre cloths.

I am truly at a loss, I cannot work with one hand on my bluetooth keyboard (which works flawlessly) and one hand on my MacBook trackpad, the only solution so far has been to plug in a super old and tatty usb-a mouse. This shouldn't have to be the solution though, it's scrolling is clunky and not smooth plus its missing all my Magic Mouse gestures that I'm used to.

I have noticed that the mouse does this whilst in different locations which shuts down any interference possibilities.

The Bluetooth module appears to be completely fine as I can airdrop without a hitch and my new space grey keyboard works flawlessly too, it also connects within half a second, where as the mouse can take 5-10 seconds.

Please does anybody have any solid recommendations? Apple have had no interest in helping fix this and persistently tell me I need to reinstall Mac OS which I clearly have done.

I managed to capture what the mouse is like during "lag" - https://youtube.com/shorts/m7t7RtPodpI

Thank you.