Xiaomi AC2100 PPPoE fails frequently with PADO timeout

Hello guys,

My Xiaomi AC2100 starts to report PADO timeouts when initiating a PPPoE connection after a firmware upgrade to 21.02.1. After reboot the PPPoE connection can be established but after several hours the connection will drop. Any help, suggestion or comment is appreciated.

Sun Jun  5 00:40:54 2022 daemon.notice netifd: Network device 'wan' link is up
Sun Jun  5 00:40:54 2022 daemon.notice netifd: Interface 'wan' has link connectivity
Sun Jun  5 00:40:54 2022 daemon.notice netifd: Interface 'wan' is setting up now
Sun Jun  5 00:40:55 2022 daemon.err insmod: module is already loaded - slhc
Sun Jun  5 00:40:55 2022 daemon.err insmod: module is already loaded - ppp_generic
Sun Jun  5 00:40:55 2022 daemon.err insmod: module is already loaded - pppox
Sun Jun  5 00:40:55 2022 daemon.err insmod: module is already loaded - pppoe
Sun Jun  5 00:40:55 2022 daemon.info pppd[3756]: Plugin rp-pppoe.so loaded.
Sun Jun  5 00:40:55 2022 daemon.info pppd[3756]: RP-PPPoE plugin version 3.8p compiled against pppd 2.4.8
Sun Jun  5 00:40:55 2022 daemon.notice pppd[3756]: pppd 2.4.8 started by root, uid 0
Sun Jun  5 00:40:56 2022 daemon.notice netifd: Network device 'wan' link is down
Sun Jun  5 00:40:56 2022 daemon.notice netifd: Interface 'wan' has link connectivity loss
Sun Jun  5 00:40:56 2022 kern.info kernel: [   54.909065] mt7530 mdio-bus:1f wan: Link is Down
Sun Jun  5 00:40:56 2022 daemon.err pppd[3756]: select (waitForPADO): Interrupted system call
Sun Jun  5 00:40:56 2022 daemon.warn pppd[3756]: Timeout waiting for PADO packets
Sun Jun  5 00:40:56 2022 daemon.err pppd[3756]: Unable to complete PPPoE Discovery
Sun Jun  5 00:40:56 2022 daemon.info pppd[3756]: Exit.