This is about router Archer XR500v.

When configuring the router with a GPON password in hex, it only allows me to put 18 hex chars when the maximium is 20. The router gives an error (Error code: 9007) when saving a gpon password with 20 hex chars.

This is clearly a bug, since GPON passwords can be 10 bytes long (10 ASCII chars) which in hex correspond to a string with 20 characters (and the router also says it supports 20 hex chars). See the images below for the errors.

How can I solve this? Can I have access to the latest firmware, or to the firmware source in some way so I can change it myself? Thanks a lot.

Edit: I did factory reset to clear any odd behaviour and did not work.