Every room I select and tap on returns 'No Data' and never the screen with the Add Button.
Tried in Duplex and Simplex, DRM2YSF on and off, YSF2DMR on and off, just YSF and still no joy.
I watched two YT videos of guys with an FT-2D tap on the room and get a second screen with an Add button to put the room into a Category. One guy even used YSF2DMR, selected a TG, and tapped on it to get the second screen with add button. Not on my 400

Running pi-star 4.1.6 and my DMR radio has NO issues connecting or using DMR2YSF. The 400 is challenging my patience and I'm a retired IT guy that understands this stuff. Hate to think what a noob is going through getting this to work...
UPDATE: It appears that Yaesu has removed this 'feature' from the 400 but it works fin on the cheaper FT-2D HT that the guy who made the YT video showing how to do it was using. Thanks Yaesu for removing useful features from an expensive radio. Discussed in the Facebook FTM-400 group.