I downloaded @Vector-Berlioz’s (great moniker, BTW!) file and can confirm the glissando behavior. I wonder if NP is making some assumptions about strings and the break is a switch NP is making?
I’ll keep digging…
I experimented with lowering the first two glisses down to the fourth string (NP 5.1.2) as well as turning off gliss delays. No luck. Here’s what happens during playback despite the OP’s “continuous” setting for most — but not all, interestingly — of the glisses:
[EDIT: Oops, I posted the wrong screenshot originally, corrected below.]