@Duncho The ER605 does not have an SFP port, all of its network ports are ordinary Ethernet cable ports. You need to make sure that the ISP modem on the front end has modulation and demodulation and...

@invid Hi, software controller has the latest firmware 5.3.1, you may try to upgrade and test.

@ingeborgdot Yes, a network topology diagram can help to locate the problem more clearly. You can show how all the devices are connected and what are the approximate IP addresses?

@supermarkert I remember the @Fae giving workarounds for this problem before, ah.... Found it. Here you are: https://community.tp-link.com/en/business/forum/topic/545634

@ElTom Based on your description, the isolation of devices within your network can be achieved primarily with the help of VLANs and ACLs. https://www.tp-link.com/support/faq/3091/ As for setting...

@MaxTR The dropout problems are all very similar and it is suggested that looking at these similar threads may help you: https://community.tp-link.com/en/business/forum/topic/522716...