Hikvision camera returns Device busy most of the time when getting screenshot

Hi, I’m trying to build some small app that will take screenshot if something happens. My problem is that when I request screenshot http://192.168.1.64/Streaming/channels/101/picture or 192.168.1.64/onvif-http/snapshot?Profile_1 or even the ISAPI link, they work. But only occasionally. Often the camera returns /Streaming/channels/101/picture 2 Device Busy

Not sure what it is busy with, as I can normally view live stream. It is DS-2CD2385G1-I

Not sure how to workaround it. Getting rtsp stream and taking screenshot seems overkill.

Any ideas why this happens?