If you know a good sewing service tech, perhaps where the machine was purchased, call and ask that question to be sure the right product is used. Good luck, let us know, I also use hoops from DIME.

I Googled and this is what I found:

an Oil for Use with Plastics
Silicone and PFPE are generally safe with all plastics. Synthetic hydrocarbons and mineral oils are usually compatible with most plastics, though high and low operating temperatures may rule out mineral oils.

Ich habe das gleiche Problem bei meiner Brother XE1, bei Brother ist das Problem bekannt - die Antwort war der Kunde muss damit leben :-(, also kein Service, ich habe mir den kleineren 20x30 Rahmen gekauft.... so funktioniert das sticken wieder. Mein Reparaturservice hat versucht das Problem zu beheben... hat nichts gebracht, liebe Grüße Maria

Try rubbing it with waxed paper. I don't know if it will work, but I use that on my plastic curtain rod to keep the rings moving smoothly.

I had never thought of this happening before. Good to hear there are safe products to use since so much of our sewing and embroidery do have plastic bits and pieces. Hope your Magna Hoop is now sliding in and out easily.

When I got my hoop it came with a small piece of sandpaper. The instructions said to "swipe the insert one time", then test to see if it slides easy. If not, swipe again, and continue to do this ONE SWIPE AT A TIME, until it slides in well. A tech told me that after it is adjusted to fit, a little oil will help too.