Aloha everyone,
so I noticed my hotend nozzle was moving around when printing and extruding so I removed the hotend nozzle and the bracket with the three screws. To my surprise, one of the four little screws from the back fell out and landed on the print plate. I took a look and discovered that another screw was missing. I have searched the Bambu website and amazon looking for these tiny screws and can’t find them. Anyone have an idea where I can find them?
Mahalo!
Aloha brah. 
You get new screws when you buy a hotened heating assembly. The small ones in the back come pre-installed.
The main ones are m3x10. The 4 small ones are m2x6. But you still need to find small washers. Probably easier to just buy the new assembly.
Check on the screws every once and awhile. Blue loctite might be helpful.
Had a similar issue. No idea which dimension that 4th screw went to. I replaced it with a m2 6mm, common in “m2 variety packs”, but did not have a suitable crush washer. I just sent it anyways. So far so good.