Curiously, this problem seems to have fixed itself.
When I turned UEFI back on (fast boot on, secure boot on) in the firmware settings, after the previous booting into LL in legacy mode (which worked), the problem seems to have corrected itself and I have UEFI fully operational once more...
Regards
Mike
When I turned UEFI back on (fast boot on, secure boot on) in the firmware settings, after the previous booting into LL in legacy mode (which worked), the problem seems to have corrected itself and I have UEFI fully operational once more...

Regards
Mike
64bit OS (32-bit on Samsung[i] netbook) installed in [i]Legacy mode on MBR-formatted SSDs (except pi which uses a micro SDHC card):
2017 - Raspberry pi 3B (4cores) ~ [email protected] - LibreElec, used for upgrading our Samsung TV (excellent for the task)
2012 - Lenovo G580 2689 (2cores; 4threads] ~ [email protected] - LL3.8/Win8.1 dual-boot (LL working smoothly)
2011 - Samsung NP-N145 Plus (1core; 2threads) ~ Intel Atom [email protected] - LL 3.8 32-bit (64-bit too 'laggy')
2008 - Asus X71Q (2cores) ~ Intel [email protected] - LL4.6/Win8.1 dual-boot, LL works fine with kernel 4.15
2007 - Dell Latitude D630 (2cores) ~ Intel [email protected] - LL4.6, works well with kernel 4.4; 4.15 doesn't work
2017 - Raspberry pi 3B (4cores) ~ [email protected] - LibreElec, used for upgrading our Samsung TV (excellent for the task)
2012 - Lenovo G580 2689 (2cores; 4threads] ~ [email protected] - LL3.8/Win8.1 dual-boot (LL working smoothly)
2011 - Samsung NP-N145 Plus (1core; 2threads) ~ Intel Atom [email protected] - LL 3.8 32-bit (64-bit too 'laggy')
2008 - Asus X71Q (2cores) ~ Intel [email protected] - LL4.6/Win8.1 dual-boot, LL works fine with kernel 4.15
2007 - Dell Latitude D630 (2cores) ~ Intel [email protected] - LL4.6, works well with kernel 4.4; 4.15 doesn't work