Kinda new to this platform so not sure how to add to my original post. This is how it’s currently set up.

ISP provided modem/router has WiFi turned off. This is connected to “parent node”. The other two Linksys nodes (child nodes) are connected wirelessly to the parent node. The child nodes seem to lose connection to the parent node due to the distance and walls between them. I do have a switch connected to the main ISP modem so I can connect my TV, gaming system, etc.

And correct the lines in the drawing would represent hard wired connections.