Can you restore those apps as well with Magisk? Do you need MagiskSU or something for it? I've read a ton of posts saying you can't fully use TiBu or anything with full system access, which is why I've stayed with SuperSU. If that's the case, I'll be switching Magisk today!
Actually looking through, yours is the first mention of being able to use TiBu on xda or any other site that I can find.
TitaniumBackup worked fine for me on my custom rom with Magisk (albeit a custom version from Jairus980 with his repacked kernel). The only issue I seem to be having is that my AdAway doesn't seem to actually be blocking anything even though the host file has been updated. Worked fine with an older version so may have to play around to see what actually broke it...