[SOLVED]Odd slownes since last update

Forgive me, if I have missed a topic that covers my problems (I’m on a mobile phone)
I’ll describe my setup first:
Latest version of osmc on raspberry pi 1b+, 3 and 3b+
The 1 and the 3 are connected by wire, the 3b+ is connected by wifi
Media files are shared by my nas, served via nfs and embedded using fstab, all of which worked fine before.
The database is shared via MySQL running on the nas.
The devices get controlled by Android devices using either Kore, yatse or the old official xbmc remote (still my favorite)
The pi 3 additionally provides ad blocking using pi hole, which is working very well.
Ipv6 is enabled on all devices (connmanctl still is a pain in the ass)
I’m using confluence skin in all devices.

Now the behavior:
As long as no networking aside from the controlling is involved everything is working flawless, navigation is smooth, menus load fast.
But as soon as the database and/or distant files are involved everything lags, loading lists is awfully slow (>10sec) playback start lasts up to 30sec (playback itself is fine at full hd) the playback status lasts up to a minute to be broadcasted to the remotes (no matter which one) and while playback is running, commands from the remotes take forever to be recognized (even worse when the YouTube plugin is involved)
Oddly database updates (which only are performed by the pi3) are quite fast.
I have tried altering video memory, menu resolution, reenabling RSS to keep fps up, shut down two of the 3 devices to evaluate if there might be concurrency issues, none of which showed any different results.

Any help is appreciated.
(I’m sorry if my language isn’t perfect, I’m not a native english speaker)

sorry, I was interrupted by my daughter :wink:
Logs are here:
I just realized that fps rate drops into single digit range when the lags occure.

OK, now that’s really odd,
I had (for other reasons) to reboot the nas, and now everything is working fine again (I had tried rebooting it before without any effect) even YouTube is working better (it was never really good though)