<SOLVED>Bluetooth not detecting device, LM21 (Cinn), fresh install, new laptop

[rfnreynders]

I think there is a problem with the manager.
When in preferences in mint 21 the bluetooth is visible always on, the problem occurs not to be able to connect to certain bluetooth devices.
When in preferences in mint 21 setting the bluetooth manager visibility to temporarely visible it connects everything without a breeze.
So there is a coding fault in the manager somewhere. For now just use temporarely visible for the adapter status in preferences of the bluetooth manager.

Cheers,

Rene

[markinson]

I recently upgraded my Linux Mint Cinnamon from 20.3 to 21.1 and noticed that the bluetooth icon was gone. It may have been gone for a while in the bar, but that's about it.
Before any other attempt (I found many discussions about it), I started the computer with a live edition (from USB) of Linux Mint and, surprisingly, the bluetooht icon was present.

So I rebooted and got into my Linux Mint Cinnamon 21.1 and even more surprised to find that the bluetooth icon had reappeared.

In short, a start with a live distro was apparently enough to make the bluetooth work again!

[SMG]

I recently upgraded my Linux Mint Cinnamon from 20.3 to 21.1 and noticed that the bluetooth icon was gone. It may have been gone for a while in the bar, but that's about it.
Before any other attempt (I found many discussions about it), I started the computer with a live edition (from USB) of Linux Mint and, surprisingly, the bluetooht icon was present.

So I rebooted and got into my Linux Mint Cinnamon 21.1 and even more surprised to find that the bluetooth icon had reappeared.

In short, a start with a live distro was apparently enough to make the bluetooth work again!

There was an update after LM21 (can not recall which version) was released because of a problem with the bluetooth icon. It may be your system just needed rebooted for it to take effect.

[markinson]

It may be your system just needed rebooted for it to take effect.

Actually after upgrading to 21.1 I restarted my computer several times and the bluetooth icon didn't appear at all.
I also tried launching the "Bluetooth Manager", but after a while it crashed, telling me that the service was not started or the device was not detected (I hope I remember correctly).

So I tried the live version, just to understand if it was a question related to Linux Mint Cinnamon 21.1 and my (old) computer or it depended on the actually installed Linux Mint.

What I really don't understand is how booting from a live via USB could have interfered with the installed environment. It's as if booting from the live edition "woke up" the device ... I really don't know.

[SMG]

What I really don't understand is how booting from a live via USB could have interfered with the installed environment. It's as if booting from the live edition "woke up" the device ... I really don't know.

The live system is using all the same hardware as the installed system. Depending upon whether your bluetooth is on the same card as the wireless, it is possible booting to a different system (the live session instead of the hard drive) may have changed the state of the physical card. Bluetooth is not just the software on the operating system. The software must interact with the firmware (BIOS/UEFI) and hardware. If the software does not detect your hardware is there, you would not see the icons.

[markinson]

... it is possible booting to a different system (the live session instead of the hard drive) may have changed the state of the physical card. ...

Even if I don't really understand how, I believe the same thing too.