My SBT don't see LMS

I am new to this forum but not to SB, I've had a SB3 for many years, no issue with it until it died last year, so I bought a used SBT and I'm trying to have it working properly. I've gone through many posts with the same subject, I didn't find a situation like mine, so I write. Apologies if this has been already discussed, I didn\t find it.

I have LMS 7.9.2. on my laptop connedted via WiFi to the same router I've connected the sbt to (wired ethernet connection).
I upgraded the SBT firmware, now I have the 7.8....754
The SBT connects to the internet, radio works, but the network is "not ok" when I run the Check Network, also the Repair Network has the same result.
So SBT doesn't see LMS and also MySqueezebox.com
However, LMS can see my SBT, I can use the Web Control panel and can stream my mysic to the SBT this way. But the SBT doesn't display anything, and I cannot use the SBT remote or touch screen to access my music folder. SBT doesn't see it.

I have tried all the suggestions I've red on many threads here, no change.
Any suggestion?

Thank you for your help, the music I get from the SBT in the curred, improper, way is amazing (as it was from my old SB3) and would like to use it properly!

Giovanni