Why is GrabCAD hiding my models without notice?

Recently, I was made aware by some of my followers that my models are disappearing from my collection, but the number of models is unchanged. From my account, I can see all of my models. However, if I log out or use another account to look at my main account, I see that 11 of my models are invisible. I've reached out to GrabCAD on two occasions to ask what the issue is, most recently today. They've never responded to my first inquiry, which was about a month ago. Based on previous attempts to contact them for other things, they never get back to me. Has this happened to anyone else?