Ahhh, OK.......your issue is the assembly feature [FOR FRAMES] must use the "Create Assembly Features" option, so that the parent part doesn't get modified.
You clearly can see it in Your video:
You have to create an Assembly Feature and not an Assembly Driven Feature!
(First option instead of second one)
This is a big difference.
First only exists in the assembly where else the second one only is defined in an assembly but should be stored back in the original part.
This will not work for Frame components.
Compare it with seeing a feature in the part / part drawing or not.
Such holes only exists in the assembly since the are created after welding the frame components.