Hi Frederic.
I do indeed have a solution! It ended up on a parallel thread. That dogged me for a long time. Hope this helps.
-Dave
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Looks like I've got a solution!
If you are experiencing problems with a SEQUENCE resetting to a lower value, disable CYCLING. When I did this, I was able to leave CACHE set to 50 and no longer have problems with intermittent resetting of the sequence value as described above.