I hear since years my music using Roon (Intel NUC, Roon Optimized Core Kit) and my Lumin T3. It always worked as it should. Since ca. Roon version 2.58 and Lumin FW ver. 21.2 I have a problem.
When I start a track out of T3 stand-by it will not play the track. I see on the Lumin display the track info, but the track does not start.
The only way to recover is to either power cycle the my Roon server or by power cycle my T3.
After a reset of one of the 2 devices, It works normally until I switch the T3 back to standby and the same issue happens again.
Interesting is, that the Ronn server works with my other devices without any issues. Also the T3 works with the Lumin app or JPLAY.
I also did a factory default of my T3 without success.
It seems, that there is a compatibility issue between Roon and my Lumin T3.
Roon 2.61 has just been released. The release notes refer to the problem with Lumin streamers having been fixed, and thus far, with my U2X, that appears to be the case.