Try to upgrade to 8.6.0.9 or 8.6.0.15 (or at least something more recent than a .0.0 version). There were some low-level AP firmware bugs in early 8.6 releases that were fixed in recent versions and may cause unpredictable connectivity like you see.
As well, upgrading the wireless drivers on your clients may resolve the issue. Especially with 'corporate Windows images' or vendor drivers (like HP, Lenovo, Dell, etc) it may be that you have just a bad driver that causes issues.
What RADIUS server do you use? You can check on the RADIUS side as well if you see strange things.
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Herman Robers
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If you have urgent issues, always contact your Aruba partner, distributor, or Aruba TAC Support. Check
https://www.arubanetworks.com/support-services/contact-support/ for how to contact Aruba TAC. Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or Aruba Networks.
In case your problem is solved, please invest the time to post a follow-up with the information on how you solved it. Others can benefit from that.
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