video – What can I do to debug and avoid decoding artifacts with RTP in ffmpeg?

I do encoding and decoding of a VP9 RTP stream programmatically, and I am experiencing occasional colorful artifacts like these:

In the ffmpeg log (both when using ffplay and my own code), this usually coincides with such messages

[sdp @ 0x14de06880] max delay reached. need to consume packet
[sdp @ 0x14de06880] RTP: missed 18 packets

So presumably, the demuxer can’t wait any longer for packets and the decoder produces something incomplete. Is there a way to either detect this and drop incomplete frames or what should I be looking at to fix this?

The VP9 support in ffmpeg’s RTP is apparently experimental, so maybe that is also a problem, but I am hoping there’s maybe some decoder parameters that makes it degrade more gracefully.