I have a Vero4K and everything was smooth until the Leia Update. With Kodi 17 I had no problem with H264 or H265 encoded files, they played just perfectly. Since Leia (I only use the automatic updates), I find that the picture is choppy, especially, when movement is going on in the scene. I do not know if this is called frame-dropping or what the correct term is, I just have a choppy playback (sound in every bitrate is fine though).
The videos come from a FreeBSD server with a sub-par Ethernet performance (only powerline possive in my house unfortunately). However that was never an issue with pre-Leia Kodi.
With earlier versions I have edited advancedsettings.xml, in order to increase cache size, I do not know, however, if that was changed by the new Leia installation (file creation date is 19 May and my edits were in 2018). The current cache section reads:
<cache> <buffermode>1</buffermode> <memorysize>524880000</memorysize> <readfactor>5.0</readfactor> </cache>
Perhaps this is the default for new installations anyway.
I will try playing the file via USB and post again.
Thanks for your help, I love the box, no matter what.