Following a re-installation of Tumbleweed (KDE) I now find that neither of my Bluetooth mice are detected when I attempt to ‘Add New Device’. Wasn’t an issue before I performed the re-installation.
The same two mice are instantly recognised if I do same with a second Tumbleweed PC.
Any suggestions, please?
Is your BT device active? Cycle on off /airplane mode
Is the mouse in pairing mode?
Can you detect the mouse with your phone/tablet?
Yes, in pairing mode, detected by phone AND a second Tumbleweed PC. So issue relates to the PC, not the mouse.
If you toggle airplane mode on and off
And then do a
dmesg
the last lines In the terminal of the prompt does it show wifi and BT status change?
Airplane mode on:
[13142.593842] wlp0s20f3: deauthenticating from ec:f4:51:75:41:05 by local choice (Reason: 3=DEAUTH_LEAVING)
Airplane mode off:
[13142.593842] wlp0s20f3: deauthenticating from ec:f4:51:75:41:05 by local choice (Reason: 3=DEAUTH_LEAVING)
[13212.011760] wlp0s20f3: authenticate with ec:f4:51:75:41:05
[13212.020970] wlp0s20f3: send auth to ec:f4:51:75:41:05 (try 1/3)
[13212.086518] wlp0s20f3: authenticated
[13212.088647] wlp0s20f3: associate with ec:f4:51:75:41:05 (try 1/3)
[13212.108020] wlp0s20f3: RX AssocResp from ec:f4:51:75:41:05 (capab=0x1031 status=0 aid=3)
[13212.119720] wlp0s20f3: associated
[13212.246150] IPv6: ADDRCONF(NETDEV_CHANGE): wlp0s20f3: link becomes ready
Not that this manes anything to me! 
Starting from basics. Show if bluetooth is maybe blocked:
sudo rfkill list
[sudo] password for root:
0: hci0: Bluetooth
Soft blocked: no
Hard blocked: no
1: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no
I also have a Logitech Bluetooth keyboard connected, no issues.