Today we've released UTM 9.508. The release will be rolled out in phases. In phase 1 you can download the update package from our FTP server, in phase 2 we will spread it via our Up2Date servers.
As part of UTM 9.508, the wireless firmware is updated to 11.0.003.
Updated from 9.506 to 9.508, MTU auto discovery previously disabled on WAN interface. After applying up2date's, MTU auto discovery is still disabled on WAN interface.
TLDR -> Interface MTU settings retained after applying this update.