This issue has been happening with all versions of studio one in the last couple of years. I just sent a bug report to them but they just respond by telling me to check in any support seen here but when I do it's just people complaining about it with no answer to the problem. This happened to me yesterday again when I was working with a client. Joe Gilder just did a video about how to comp tracks this way and I made a mention in the comments about how this bug still exits. It sounds like it hasn't been fixed in version 6 either. It also seems to happen totally randomly