Ugh, been there (just set a 30-minute timer before asking for help).

Classic DIY tension problems, I mean. Scrap wood can warp over time and throw off the hinge alignment, making it act like a spring. Maybe adding a simple latch or a thicker rolling pin could stabilize the pressure. Idk, my cousin's homemade press did the same thing and we had dough on the ceiling for weeks.

Describe when the shaking stopped.

Oh it reminds me of when my old hard drive died years back. Lost all the baby pictures from my son's first year, the ones before we used the cloud. Still kicks me when I think about those particular photos just gone.

Consider if magnetic sheets really cause that many jams. I've used them for years without any problems on my basic inkjet. Maybe it's just a rare issue that gets blown out of proportion.