i used to get these, but since upgrading my gfx card, to a zotac 1660 ti amp edition from a zotac 780 ti, not any more, i think it comes down to, server speed connection, players computer specs in processing the info before trying to draw on screen, if it misses a beat, it kind of guesses whats there and draws a default block image
i still only got 16 gig ram though and an average 4 core cpu and motherboard,
but my dedicated server is amazingly fast cpu and connection speed, so all of that all helps
7dtd game needs quick thinking processing and server side information "sending" enough for the players comp to process quickly enough to display correct images, all this adds up and is needed to run as best as possible, any slight confliction/delay or mis processing, creates these glitched images