Thank you for replying.
I do have spare tmc and same issue.
Reason i do not use 9.702 is due to the vehicle selection issue where it disappears after first use, thus always used 9,701.
Unless there are other versions i can use.
I found using official 9.701 then patching make the traffic work on earlier and later models, whereas customised, traffic will not work at all.
This is first time i have used the internal of the go models to use maps and maybe it might be this?
but i have found recently on both early i.e 520, 530, 720 etc and later go models i.e. 540, 740 etc, using both a rds tmc receiver charger & plug into unit rds tmc receiver, that they are disconnecting and traffic bar disappears.