I have migrated an install to LE 10.95 to see what would happen and I believe I found a bug with IPTV Simple Client
I use streams from FrndlyTV as well as streams I add from iptv-org/iptv: Collection of publicly available IPTV channels from all over the world (github.com)
I use this script to login to FrndlyTV and get the channels
matthuisman/frndlytv-for-channels: Frndly TV for Channels (github.com)
I also run IPTV Merge Kodi addon to merge my customized iptv-org list and FrndlyTV list. This list is written to a NAS where it is accessed by different Kodi systems.
All worked perfectly well until Kodi 20/ LE 10.095.x
On Kodi 19 I was always able to get the highest quality streams 720P (for FrndlyTV cannels) or 1080p (with the two streams below) with no issues.
Now on Kodi 20 I get reduced resolution. (see attached screenshots of the same exact channel playing on IPTV Siple on Kodi 19.x vs Kodi 20) These screenshots were from the History Channel on Frndly TV (720P) where I first noticed the issue. You can see the difference in "resolution" in On Screen Display
Screenshots from Libreelec Generic x86-64 on Intel hardware Chrombox CN62 running Mr Chromebox
So to compare, I had the following channels in my manual list from the huge list at IPTV-ORG github These are both 1080p streams (confirmed on Kodi 19) however on Kodi 20 (on Windows and Librteelec) only reproduce at 720p
#EXTINF:-1 tvg-id="AlJazeeraEnglish.qa" tvg-country="INT" tvg-language="English" tvg-logo="https://nologo.com/logos/AlJazeera.png" group-title="News",Al Jazeera (QA)
https://live-hls-web-aje.getaj.net/AJE/index.m3u8
#EXTINF:-1 tvg-id="NHKWorldJapan.jp" tvg-country="INT" tvg-language="English" tvg-logo="https://upload.wikimedia.org/wikipedia/commons/thumb/7/7b/NHK_World.svg/512px-NHK_World.svg.png" group-title="News",NHK World (JP)
https://nhkwlive-ojp.akamaized.net/hls/live/2003459/nhkwlive-ojp-en/index.m3u8
Upon additional investigation........
I installed Kodi 20/IPTV Simple on a Windows machine and found the exact same limited resolution playback (720p) so the Bug goes back to Kodi not LE. It is worth noting however if you ever post on the Kodi forum and so much as mention Libreelec you are likely to be attacked for trying to get support for LE on a Kodi forum, even if you have already found the same bug on Kodi (without LE). I therefore leave it in this forum's capable hands
I think with the above two streams on IPTV Simple , anyone can easily reproduce this bug on Kodi or on Libreelec by comparing IPTVSimple on Kodi 19 vs 20
Note the "resolution" in screenshots