Yes
More or less annoying than watching a file with stuttering? Capture 2 minutes of the file stuttering with debug enabled them upload the logs. We’ve provided clear instructions in the link. If it was anyone’s intention to have people annoyed then we would simply be ignoring this thread instead of attempting to help.
If you activate it via command line by editing advancedsettings you can enable debug logging without the OSD
<advancedsettings> <loglevel>2</loglevel> <!-- Change this to "1" to hide the on-screen debug log text --> </advancedsettings>
Sooo…
Today I had some time to get to the topic.
As we already said, we’re now focussing on HIS Pi
First:
I set the onboard WLAN with Drivers on the Blacklist, resulting in that the Pi only uses the Dongle now.
Second:
Wavemon was installed. He spits out a signal + quality, but he doesn’t show the graph for the Dongle.
Important to notice: After Boot, the quality of the signal is volatile. from 20-80% After 5 minutes, it calms down and floats around 50-70%. Closing the wooden door (which has a small glass plate in it) doesn’t affect the signal.
As I use a repeater on my floor, it plugged it in in his room, set everything up - still no change in Signal. Around ~50-80%. Repeater shows full signal on its side.
Fun Fact: When I take his Pi up to MY Floor, with repeater and everything, connected to HIS WLAN, I got stable 90-100% Signal Quality and fine playback - although it was at my PC in my work room, not my living room.
Third: Checked on that Power Supply. Aukro 5V 3A Power Supply. Was my mistake last time. It has 3 Amps.
So… Lets test those movies again. This time, HD Asterix, ~4 GB.
Started it and… Stutter. Made some more tries, checked wavemon etc… So - with debug enabled, I made a log file.
https://paste.osmc.tv/oculanomet
After that log, I disabled debug log, rebooted, started the film again… first 10 seconds, stutter… paused it, talked a little bit, resumed - it worked out fine. Even when fast-forwarding 30 minutes (which should definitively need another time to buffer) it worked instantly at that spot. Made some jumps forwards and backwards in the movie… No problems at all. Was the same movie all the time.
Oh… and all movies work out fine when they’re played locally with USB Stick.
Hope this one spits out some information.
Thanks again to all of you for your help 
Why not disable it via dtoverlay?
Also suggest to test network throughput with iperf3 over eg 10 minutes.
WiFi signal below 60% will cause scanning due to roaming.