You’re using 40mhz channel width, turn that down to 20. 40 is just asking for 10x the interference and signal quality problems. Also looks like all your mesh nodes are pretty strong signal, you actually have too much wifi going on, which will cause problems as well. With a mesh system there should be a small amount of overlap, not all competing strong signals (especially when they all use the same channel like Orbi does). You probably have twice as many nodes as you need.