I have the 1617EVS mounted in a router table, and 1613EVS which was purchased before I built the router table.
They have the same collet.
Providing this as FYI. I do not think this is your issue, just passing along.
I have experienced the collet coming out of the nut. In my case it was while the router was stationary and without a bit in the collet. In fact the lack of bit may have been the root cause.
I found out if the collet is empty and I tighten the nut too much, the collet compresses - as designed - but if compressed too much, it falls out of the spring clip. Oops.
It was not difficult to get the collet back on the spring clip, but lesson learned.
If the collet is empty, I do not tighten the nut, just screw back on loosely.