Tvheadend

Probably best if you investigate why you are loosing connection to your TVH backend server. If you are using WiFi try swap it for a wired connection. It definitely sounds like an OSMC problem. Your tuner could be a problem too. Try posting on the OSMC forum or you could try installing LibreELEC instead.

Thank you for answering
I shall try a wired connexion ans, if necessary shall post on osmc forum

I tried a wired connexion. Same problem. The functions of TVheadend are altered after some time running.
When I restart it, it seems to be functionnal again. As example, I give two screen captures , one before restart, the other after. The status is readable again..

Make sure your tuner antenna is correctly positioned for best signal and you can check this by looking at the signal status in TVH while moving your antenna around.

Maybe your tuner is beginning to fail. It does happen. You could try connecting your tuner to a different computer to test it.

If your tuner does not have its own power supply it may be overloading the RPI power supply. In an SSH session with your tuner connected run the command dmesg to see if it reports an under voltage error. If so you will need to replace your Pi3 power supply with a larger capacity one.

Yes I used the command dmesg and I noticed an undervoltage error. I changed the PSU and now there is no more error. Nevertheless, in "status" tab I cannot read S/N ratio and signal strength for more than 3 or 4 minutes, after that all information on this screen disappear. Thank you for your help, I am one step further.

You may still be experiencing a power failure on your tuner even though you have already swapped it out. That would explain a possible drop off in signal level status bar. Try running dmesg once the signal status level stops displaying a signal.

It seems that having changed the PSU for a more powerful one and used a wired connexion to the lan has made my server far more stable. I have a persistent signal strength indication.
Thanks a lot for your advices

Any sudden drop off in connection like that usually points to power supply issues. The RPI boards with attached peripherals are usually the culprit. You can never have enough amperage when it comes to scenarios like that. You probably didn’t believe me after you changed your power supply once. Now you can see the difference.

I gave up with my previous configuration, it was unresponsive and worked everyday worse.
My Idea was to install tvheadend on linux OS without anything else ( I didnt use osmc at all).
I started from scratch and installed raspbian bullseye.
After that, I installed tvheadend through snapstore ( Tvheadend 24 last updated from 4.3-1994~gc7b713edb).
I made a try and could never record a stream. I realised that the owner of the directory ( home/hts) shouldn't be the right one. I modified the owner and from that moment, everything seems to be ok. I Can record from lan and web and the system is always responsive and the status of the tuner is ok with SNR 28 dB and signal strength 93% .
Thank you for your help.

TVH installed from Snap can be a bit clunky. I suggest installing it via apt from the PPA https://launchpad.net/~mamarley/+archive/ubuntu/tvheadend-git

The main drawback of my installation was the SD card. I settled a 60 Go Ssd and bullseye OS on it. From that moment, everything ran perfect, I could even watch TV programs on external devices such as my phone. The stream is unregular with constant latches but it works. The status indication of my dongle is absent except when watching a program, at such moments it shows correct S/N ratio and a signal strength of somewhat 94 %.
Thank you for your help

Make sure you make a backup copy of your SD card. They are very prone to failure.