from Bern to London

Hello everyone

I plan to travel from Bern to London via Paris on June 9th. I’ve already made the booking for the 15.12 Eurostar service from Paris to London.

Now I found this interesting connection from Bern but I’m a bit worried about the transfer time of only 9 minutes:

RE 18122 Bern 06.23 → Frasne 08.06

TGV 9264 Frasne 08.15 → Paris G.d.Lyon 11.08

Has anyone any experience with this connection? Is the connection guaranteed? My alternative would be travelling via Basel and Strassbourg as trains are more frequent on that route. But the transfer time in Strassbourg is also not too long.

Which route would you prefer? I only want to catch the Eurostar in Paris.

Thanks in advance for your help.