WAN connection continuously drop (GL-MT3000 Beryl AX)

And with this Dlink switch same problem appear again...
Why ? This is not the same parent network port and device than previous...

Tue Jul 23 11:28:06 2024 daemon.notice netifd: Network device 'eth0' link is down
Tue Jul 23 11:28:06 2024 daemon.notice netifd: Interface 'wan' has link connectivity loss
Tue Jul 23 11:28:06 2024 kern.info kernel: [ 4726.632126] mtk_soc_eth 15100000.ethernet eth0: Link is Down
Tue Jul 23 11:28:09 2024 daemon.notice netifd: Network device 'eth0' link is up
Tue Jul 23 11:28:09 2024 daemon.notice netifd: Interface 'wan' has link connectivity
Tue Jul 23 11:28:09 2024 kern.info kernel: [ 4729.705246] mtk_soc_eth 15100000.ethernet eth0: Link is Up - 1Gbps/Full - flow control rx/tx