I have the same problem! Have tried all the suggested things to do, delete the app, revoke and allow...etc. Going nuts here. :D

I know crazy,which country are you in?

Yup, me too have this issue. A Suunto lover from Malaysia 

I have the same problem since yesterday. 
I deleted the app, reboot and it’s still not working. 
I am from France and I hope it’ s will be resolved soon. 

Hello and thanks to everyone who posted here. 

We are in the process of investigating this issue, and will share an update here when we know more. In the meantime, thank you for your patience.

I try to link an activity and there is no way. 

In the Suunto application yes. But not from Suunto to Strava.
Yesterday while I was transferring my activity to Suunto, an update for the watch software appeared, I installed it correctly but the activity to Strava does not load...

Yeah. Haven’t been syncing automatically from Suunto app to Strava since yesterday. I assume something broke when Suunto updated their app. Only way to sync currently is to manually upload .FIT data from desktop.

Same here. Starting today, my activites from Suunto are NOT being uploaded to Strava. I really hope this gets fixed ASAP. Thanks. 

Good Morning to all. It Seems that there is an Issue with Suunto. There are two training sessions on 18th and 19th of December which are uploaded on my SUUNTO 5 and on the Suunto mobile App but not on Strava. I did uninstall on both Strava and Suunto apps just in case but wasn;t fixed. 

Hello! Thanks to all who have posted here and thanks for your patience.

We have heard from Suunto that an issue on their end has caused delays with syncing activities. They are in the process of getting caught up with this backlog and your missing activities should sync to Strava soon. If you do not see them by tomorrow (Dec 21), please reach out to Suunto Support directly for further assistance.