There was a new version of movies123 today, version 2.0.1. Do you have that?
Also there are issues with movies123 and working urls. The general advice on the ares project forum is to avoid that addon until such time as those issues are resolved.
In answer to your other question, I use a t8s plus, a t8 mini and a t8, in different rooms obviously.
Apart from the t8 which runs dbmc 16.3, the other two boxes run 16.6.
I am running the following versions:
Zem: 6.2.8
Spectro: 2017.01.20.2
Salts: 2.0.136
I have tested all 3
Salts: trending movies, La la land Result: found working sources (some need pairing),
Specto: in theatres, La la land Result: found working sources
Zem: sports365, Liverpool vs Southampton : Czech language commentary. Result: works fine (clicked on sports365 web site - live now - on box browser first to avoid 2 minute time out)
Conclusion. Dbmc 16.6 not the problem