[PLASMA 5] Bluetooth Broken/Regression? after update to 18.04

[vtpoet]

Can't connect to any of my bluetooth devices.

1.) Choose bluetooth device to connect to.
2.) Kubuntu states that connection has been achieved.
3.) My bluetooth devices all report being disconnected.

Workaround:

1.) Remove device from list of available devices.
2.) Search and re-add the device to list of available devices.

I have to do the workaround every time I want to reconnect a Bluetooth device. I've been Googling this:

https://www.reddit.com/r/linuxquesti..._kubuntu_1804/
https://bugzilla.kernel.org/show_bug.cgi?id=197147
https://bugs.launchpad.net/ubuntu/+s...e/+bug/1756824

But none of the other workarounds work. Anyone else know anything about this? Bluetooth worked beautifully in 17.04. In 17.10 it was squirrely but still worked.

[DrGeoffrey]

At least I'm not the only one seeing this problem. Thanks for inquiring.

Follow-up. This may not add much, but I am finding what appears to be the same problem with Tumbleweed.

[vtpoet]

Yeah, sounds like a Kernel level regression.

In my experience those can take months to be fixed, let alone acknowledged.

I'm going to experimentally downgrade the Kernel to 4.10 and see how that works. Kubuntu 17.04 and 4.10 were almost flawless.

[vtpoet]

Update: Downgraded to Kernel 4.10.17

http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.10.17/

And Bluetooth works like a charm. Everything else, so far, is working swimmingly. Kernel 4.13 (Kubuntu 17.10) would probably also work and be more recent, though I frankly don't think it makes one iota of difference as far as a user like myself is concerned.

More information. Went back to read this thread:

https://bugzilla.kernel.org/show_bug.cgi?id=197147

And though I couldn't understand it all, it appears the issue (which sounds related?) affects kernels 4.12 and up. So best to downgrade to the latest 4.10 it seems? Either that or someone better than me can make sense of the thread's instructions (updating firmware and recompiling the kernel) which seem only partially successful. Downgrading seems simplest.

[vtpoet]

Scratch all that. After downgrading, the same problems crop up. Bluetooth is a mess in 18.04... Any ideas?