@me61ic It is possible your Deco mesh runs out of IP addresses, due to devices using "MAC address randomization." To confirm (or dismiss) this theory, assign static IP addresses to both Fire TVs and...

Juzcat wrote @Alexandre. I have an ISP provided Huawei modem. Echolife HG 8240H5, which connects to a TP-Link Archer AX72 as the router. @Juzcat Good router, but it only has gigabit Ethernet ports....

@ccrapp I had similar setup to what you will: ISP router with external drive connected to USB3 port, and Deco mesh running in AP mode. Everything worked just fine: external drive and ISP router were...

@Eric1067 Someone else had a similar issue I tried to help with, and as strange as it may sound, at the end they said replacing Ethernet cable which goes to affected Deco fixed the problem. See...

@wizzardlizzard Check if IPTV feature got enabled in your Deco mesh. If it is enabled, see if you can disable it. More about that feature here: How to Configure IPTV function on Deco

@Juzcat Do you have ISP modem or ISP modem/router? If it is just modem, what did you use for router before Deco mesh?