UK TMC is more trouble than it's worth.

Crash that happened 8 hours ago? Not on TMC becuase the Police want to keep the traffic on the motorway and out of the villiages.

Crash that was cleared yesterday? Stilll on the TMC.

Queue on the M25? Redirected onto the A406 which is stationary but there is no traffic data coverage and so it looks like an empty A road to the GPS.

You are better off with the local radio traffic reports.

In Germany/France, TMC works well. It's up to date, with detailed information such as "traffic contraflow, average speed 50MPH, roadwors for two weeks starting from xxx".

Try tuning your radio to Classic FM and leaving it there for a while to see if the TMC updates. The data rate is very slow.