Logs, if needed, will be up once I finish taking care of the tasks that had piled up since last week,

Yes please! dmesg especially

Sorry about the delay, I finally caught up.

Since I could not think of any other logs to record, only dmesg has been recorded.

Additionally, I can confirm that the AX200 is perfectly fine with 5.15, as I have seen with my desktop.

This is a separate issue, however it appears that under Linux 5.14, Bluetooth LE does not appear to be working on the AX210.

I just received my new mouse (Lenovo Howard), which is a dual-mode mouse (2.4Ghz dongle+BT/BT LE), and while it works fine with standard BT (via the 2.4Ghz dongle, no issues whatsoever), it fails to pair via BT LE (or as Lenovo calls it, BT 5.0, as opposed to BT 3.0).

There is nothing in dmesg (aside from Bluetooth: hci0: setting interface failed (110), which only happens once, and does not correspond to this at all), while bluetoothctl generally only shows Device [REDACTED] Connected: yes immediately followed by Device [REDACTED] Connected: no, with the only interesting line (which only appeared once) being Failed to connect: org.bluez.Error.Failed le-connection-abort-by-local.

FWIW there are rather sizeable improvements queued up for the next bluez release (whenever that will get tagged by upstream), including quite a few Bluetooth LE fixes. Whether that fixes your particular issue or not remains to be seen though.

In T10194#194633, @Staudey wrote:

FWIW there are rather sizeable improvements queued up for the next bluez release (whenever that will get tagged by upstream), including quite a few Bluetooth LE fixes. Whether that fixes your particular issue or not remains to be seen though.

Bluez 5.64 was released yesterday.

Ah, so it's just the GitHub tags stuck in the past again.

Bluetooth LE is working without any issues with my AX200 on Linux 5.15, as evidenced from my desktop with the same mouse.

@ReillyBrogan @Staudey Thanks, though I believe this is more of an issue with the driver/firmware, rather than the software Bluetooth stack.

Update: No difference as of yet with 5.15.43, just late with the post update.

It appears that linux-firmware is woefully out of date, which coupled with Intel's firmware update cadence shenanigans, could be the reason for the AX210 not working at all on Solus, starting with Linux 5.15.

Will open a new issue.

I have absolutely no idea how this happened, however after my system failed to show anything with graphics (no crashes, just graceful termination of LightDM and XServer, with no explanation why), and reinstallation of quite a few packages (and reverting manual changes meant to enable Intel triple buffering X11-wide), suddenly my AX210 is working without any issues with Linux 5.15, and even Bluetooth LE is working perfectly.