I've just tested this using standard v1.04t firmware with les-70's config file.
That is the original config file with the remote management port set to 23 but since changed to 7574.
With Remote management enable I created a new WAN connection, including using TRO69.
The port used by remote management remained 7574.
ShieldsUp showed all the first 1055 ports to be stealth.
Sorry, I couldn't duplicate this bug.
Perhaps the original, uncorrected, open source config file was used.