If the segments are saved on your Garmin watch how should this be a Strava problem?

Not sure, but the Garmin support said that this could be a Strava issue and that they could not help me.

Hey @Johansoderblom, 
Thanks for your post. I'm not sure if this is an issue on our side, however, if you are still having issues, please submit a support ticket.  Our team can take a closer look at your account and see if this is something our our side. 

Thanks, Garmin support managed to help after several re-installations and we are not really sure what made it work eventually but for some reason it suddenly just started working.

I also just went from a Fenix 5 to a Fenix 7 and no longer have live segments. I’ve done everything I’ve read I should do. Nothing works. May i ask what they had you do that made it eventually work for you? Thanks!

Unfortunately I don't know what worked in the ended, I did several things and suddenly it just started working from one run to the next. It's probably best that you contact the Garmin support, if this is a recuring problemn they might have solved it by now. 
But this is what they had me do:
- Reconnect Garmin and Strava https://support.garmin.com/en-US/?faq=4uYoMd5zEt22rg0iehnro9&identifier=722070755&searchQuery=strava&tab=topics

- Reconnect Strava and blutooth (I got the instructions in Swedish and it was called "Bluetooth omparkoppling")

- Reconnect from the other end (not only from Garmin towards Strava but also the Strava to Garmin, can't find the instruction for it though).

thank you for your response and insight. I’ll check that link and go from there. I did have a chat going with Garmin but got disconnected. Oh well. Thanks again!