There are multiple reasons why a Roon/Tidal combination can be problematic compared to the Tidal app. Roon can be doing a lot to the database in addition to playing music.
The Core hardware, topology of your network (particularly any WiFi link from Core to Output), speed of the Internet connection, any buffer timing in Device Setup, operating system updates, analysis of new music, ISP and DNS server can all contribute.
If you can describe those things then the Community can help to identify things that have been problematic in the past and what fixes have worked.