That is NOT normal for the Roamio's.
Try doing a hard reset of the Roamio, pull the power cord, after 30 seconds or so plug it back in. If the problem persists call TiVo service.
You might just want to call TiVo anyway in case you are getting close to the end if is free replacement.
If you don't have it, get the extended warranty while your on the phone with them...just in case!
I have no experience with tuning adapters.
Sent from my LG G4 using Tapatalk
Roamio Pro- All In
Roamio- 3TB w/All In
Premiere- 2TB w/PLS
TiVo HD- 2TB w/ PLS
Connected via MoCa, Ethernet and wireless adapters.