This can be due to 2 reasons:
1. the end device on which the VR project is viewed – older smartphone models can sometimes not play back more than 4K or even HD quality. Other devices (for example, new smartphones or VR glasses) can play much higher quality content.
2. the given internet network (if the project is viewed via the web). There are also streaming differences that can lead to different quality levels.
The VRdirect platform tries to play out the highest content possible at any given time.