When using Connect, I don't see all of the comments. I was just looking at a post where the counter showed over 40 comments, but I counted them and only saw about 16. Then I opened up the same post in my web browser and I was able to see all of the comments there.
I just checked after seeing your post and found that a thread with 102 comments only had about 40 to view. Another with 44 comments only had about 33 to view.
Updated today and the comment issue persists. Ironically I see only 3 of the 4 comments on this post on missing comments. https://lemmy.world/post/2259195
Does it work for you in the browser? I might need to add a app-side comparison check against the home instance because that link (this post) on lemmy.world only has 3 comments when it should be 5 so I'm thinking 2 of the comments haven't federated over.
If I open the link with the webview I get: Couldn't load via local instance, but if I refresh, the post appears with the comment counter showing 3. a different post appears below the error message:
https://lemmy.world/post/2259195
As you can see it has the same id, but it's a different post: Missing comments posted by Avigrace five days ago in this community..
You can update by going to the app store. Clicking on your profile picture. Then click manage apps. You should now see an option to update all your apps.
You can also wait and it will be updated for you. I'm not sure when that will happen.