One of my mobile devices keeps getting blocked by the router every week or two on it's own

Router has access control enabled with whitelist, so only assigned mac addresses are connected via DHCP with same static IP and no other devices can connect unless spoofing to said mac addresses. 

Admin portal also has been locked down to single address with a long generated password, same as the WPA2 password and router logs don't indicate anything about how the device keeps ending up in the block list, last access is always last time I used the portal and nothing appears unusal with the logs. 

Could it be some kind of packet filtering, ISP overwriting settings or a rouge software might be at play? Also might be worth mentioning router is connecting to internet via a HUAWEI 4G Modem though doubt that would be the problem, device that always gets locked also only sends traffic over a single port using wireguard, all other devices connect without any port blocking other than http.