If you are using Manu design solars and powerlines, that’s the culprit! I had the same problem! disabling this mod, all fine.
Are you using a Rolling Cache, and if so, have you deleted it?
(Just exit sim, delete …Microsoft.Limitless_8wekyb3d8bbwe\LocalCache\ROLLINGCACHE.CCC, restart).
This seemed to fix some stuttering for me about 3-4 weeks ago, prior to SU5 (I did not enroll in the beta).
I was getting 5+ second hard freezes 2 nautical miles away from pretty much every airport no matter what I tried, but disabling these two add-ons seems to have fixed my issue. Thanks!
Hi Steve - yes Rolling Cache got deleted and recreated. Thx 
Hi! Unfortunately I am not using it - but looking into Addon-Linker sent a chiver through my spine anyways - over the years we do accumulate quite a bit do we? ^^
Interesting. I have the powerlines addon. I will try disabling to see if it works.
Take it more to every Manudesign addon. They are all very nice! But there is something changed in how su5 talks to theese addons. Disable all from Manudesign and freezes will be gone!
For anyone experiencing freezes with my global add-ons, it has been reportet that SU5.1 (new beta) seems to fix them, might be a good idea to jump on the beta and have a try 
I experienced a couple weird long pauses in the sim on my flight this evening and it wasn’t doing that until SU5. Once on departure and then once on approach that almost made me think the sim was about to CTD. I’ve been getting that kind of thing often since SU5.