Modifying a Sketch deletes Components/Bodies that have nothing to do with the sketch

[Squaredem]

Hi, I'm relatively new (about 12 months) to Fusion 360.This is my first intricate model. When going back to modify a sketch, it occasionally  affects other Components or Bodies. Usually I don't notice it until it's too late and I have to spend a lot of time fixing it. I don't know what I'm doing wrong (or even if it's me). Any help would be appreciated so I prevent this in the future. ive attached a screen recording and a link to the file to help understand what's happening. Thanks in advance. 

[cpinatel]

Ah ! I am not the only one having this issue !!!  I agree, this is terribly annoying.  I just started a thread on the same subject, I actually missed this one.

One thing which is strange though is that the parameters for the sketches, intrudes and other functions are still in the manage parameters window.