Hey there! I’m not from the Prusa Support team but may be able to help.
Because the filament sensor is pretty important, I suggest making sure it’s pretty tight. Since I’m not from the Prusa team don’t take my word on this, but looking at the manual I suggest going/skip to Step 48 on the e-axis (assuming you have a textile sleeve and not a spiral wrap, otherwise it’s Step 50) and see if the filament sensor still wiggles around. If it doesn’t (like actually doesn’t move more than a fraction of a millimeter), you’re all set. If it still jostles around, then you should disassemble the extruder-idler piece (basically undo step 11) which gives you access to the screw that holds the sensor in place.
I hope this helps, and good luck!