I have just installed my new Form 3, but there are some problems (I think with the mixer). I have followed the instructions carefully and done a firmware update but the problem remains. As soon as the mixer goes to the right it looks like it is going too far and then it comes loose from the magnet and then it pops up from the magnet. And as soon as the laser underneath goes to the left again, the magnet does take the mixer back, but as soon as it is completely to the left, it is stuck to the tank and the magnet no longer takes the mixer with him, after that I get error message.
I had this exact issue. I contacted support and they replaced my tank and mixer arm after I sent videos of it happening, and the issue was resolved. You may also find that if this is happening in a “dry” tank, that adding a little resin in will likely help. When I added in resin the mixer arm was more likely to stay seated where it belonged. However even after adding in some resin my mixer arm was still acting up, particularly after a print was finished, thus why my tank was replaced.