I’ve seen that when I used a bump node with a normal map texture. Also sometimes happens when I plug a normal map texture directly to the normal socket without the normal map node. Also do you have any alpha or transparency going on?
As for node limits, back in 2.80 32bit version it had a limit of a little more than 64,000 nodes and 256 texture nodes(including image texture) with eevee on a minimum spec PC. So, I don’t really think that’s a problem, but if it is in 4.1(it may may be 4.2) there is an overlay that tells you how many millisecond each node use. I don’t remember if you have to check developer extras in the interface section of preferences or not. That along with right clicking status bar and checking VRAM to see how much is being used is were. I’d start.
