Hello,
It sounds like you are hitting a management hang. We fixed that in P.1.16 as far as I remember, so please check that the update completed and you are actually booted into P.1.17 on the boxes that still give issues.
Looking in our system I have not found a currently active case for management hang on the V1810G, but it is possible you are hitting a corner case that is not included in the previous fix.
If that is the case (i.e. you ARE running P.1.17 on all the devices), then I'd like you to log a case with support so this can be root cause analysed and resolved if a software bug is found.
Kind regards,
Michael Olsen