Relay`s blinking behavior

Hi there. Recently, some of my relays connected to Ewelink have started blinking. I’ve never seen this behavior before. The entire system has been running for 5 years, and everything worked perfectly before. I have a advanced plan. The MINIR4 and DUAL R3 devices are blinking, as is one oh the TH Elite. By blinking, I mean a partial loss of network for a few seconds. It appears/ seems offline, then recovers on its own way somehow. I’ve set up a static network Ips for these units on my router, but it doesn’t help. What can I do? Thanks in advance.