Hi,
When I try to configure the timeshift buffer in TVHeadend 4.3 Alpha or 4.2 it does not hold the enablement flag.
Sometimes the fields completely disappear, or just the Advanced section disappear - see the attached image.
Anyone else se
Make sure you have admin user rights on the tvheadend account you are using to change the settings...and also check the set location for your buffer if you r using a diff location rather then default...make sure tvheadend can write to that location..
Is it this 4 years old bug 
Bug #4487: Timeshift webui bug - Tvheadend
To workaround:
User interface level: expert
Persistent user interface level: yesI would recommend to use Tvheadend 4.2 as 4.3 has more configuration & function issues in LE and (from my point of view) no advantage.
Some config issues also depends on web browser used.
I would recommend to use Tvheadend 4.2 as 4.3 has more configuration & function issues
yea but at the same time a lot improvements
its 50:50
I am using both versions but I am sorry I can't really point out any improvement in 4.3 (that I could appreciate). 
Instead there are really strange issues with Networks / MUXes configuration (it depends on web browser used) and worse compatibility with Kodi (so for instance subtitles are not displayed on some MUXes despite recorded properly).
Both have an issue with 'random' EPG records corruptions (don't know if it's country / language related or what's the reason) and timeshift buffer issues.
But in general, both usable as soon as you went through the config nightmare of 4.3.
