I had the exact same problem. I have a solution for this. Go to installer and install Biggboss's beta/experimental thingy. Once you do that it will allow you to install 1.1.3 ringtone fix under tweaks. It should work for all default ringtones. If you use marimba be sure to choose the one in the middle, the on on the top doesn't work. Remember it's still beta so it may not always work, but it worked like a charm for me. Cheers.