Thanks for the details provided, please answer the next questions:
1:Is the connection constantly dropping?
2:If you connect your computer directly to the culprit router, does the connection work fine?
3:Do you experience a power outage or similar before the issue started?
4:If you have access to the Unleashed APP or the Unleashed dashboard via web browser, check if you can see the switch, and if the name appears as ICX7150-Router instead of ICX7150-Switch, you may be experiencing a known issue named routing code. This means that the Switch is booting from its routing partition causing the connection issues you have, so you need to follow up next guide:
How to Fix Routing code issues on Lennar Home users via Web GUI.
Note: before you gain access to the Switch, your computer, or even phone must be connected to the internet, because must have connectivity to the Switch IP address.
Technical Support Engineer | L2 TAC Wired