How to confirm if the issue is caused by a MoCA-DOCSIS frequency conflict?

Check ISP equipment specifications: Contact the ISP to confirm their DOCSIS frequency plan (e.g., High-Split or Full Duplex DOCSIS configurations). 

Install a MoCA filter: Add a MoCA-compatible Point of Entry (PoE) filter at the main coax input to prevent MoCA signals from leaking into the ISP line. 

Observe disconnection patterns: If disconnections occur only when the MoCA device is connected and resolve when removed, this strongly indicates frequency conflict.