I now tested from #0130 on backwards to elder versions:
Last working version for me is #0117.
With #0124, powering off my TV results in a permanent CEC issue. TV doesn't recognize kodi as CEC source any longer then. Powering off TV from mains between version switches make things worst (for me as user) because my TV simply doesn't recognize kodi at all in this case (TV CEC menu shows "No Source" and "TV" as selectable sources but no more item namend "kodi" after powered on again) until I reboot libreelec WHILE TV POWERED ON. Then TV recognizes "kodi" as CEC source UNTIL TV POWERED OFF again and so on.
While I now have reinstalled #0112 and #0117 for a few times I can say for sure that I myself DO NOT have to select "kodi" as CEC source once after libreelec testbuild version switches and therefor I can repeat that I am pretty sure I never had to do this before (after testbuild version switching). I was wondering why then I never would have recognized this before
Maybe I only need to reselect the CEC source in my TV's menu after CEC has been altered, and all testbuild versions which I used before (since switch to Leia) have been using the same CEC protocol and have been working fine for my setup.
Issues start for me with #0124 (moving backwards from #0130 as starting point, so #0129 has the problem, #0128 has the problem as well and so on up (or better: down) to #0124 while #0117 is the latest version which works okay for me).
I can easily see this right after restarting libreelec and powering on my TV because everytime I have such a "CEC issue version" of libreelec my
TV AVR doesn't preselect kodi as source and therefor switches to TV as the last known hdmi source (instead of libreelec). With "good" libreelec versions my AVR doesn't switch its signal source from libreelec to TV. (of course I also checked CEC ability via more usual ways).
I would test all the versions in between as well, but unfortunately I have to go to work now.
BTW: I noticed for some version (might have been #0128) input signal switched from 1080p to 1080i. Just mentioning this because some people seem to have problems with interlacing and artefacts since newer versions)