My Photo Stream Folder is Missing in Photos app in Mohave

Some are jpeg, some are HEIC. How did they get to the HEIC format? I am not familiar with that format.

I have some photos that are JPEG, others HEIC, others have copies in both formats? What is going on ?

I found how to stop saving images in that format (Settings on iPhone). Maybe that's why stuff was not getting to Photostream? But that has been inconsistent.

And there is still no My Photo Stream folder in Photos on the iMac.

Does this mean I would add a new user account on the iMac? (with a new Apple ID?)

This is my regular user account view of Photos menu.

This is how I have always had iCloud set for Photos:

I will look at fixing permissions.

Thanks.

Photos app is set the same way. Always has been. I've changed nothing (except loading Mojave) and something broke. I have not had time to check permissions fix yet.

I did as you suggested. The Photos app in the test account has a different menu than in my regular user account. See screen capture. The Photo Stream folder was slowly loading the same photos that were already in my regular account photos folder. There are still photos on my iPhone's Camera Roll (which is set to jpeg) that are not getting loaded into My Photo Stream on the phone (which is really on a server before they go back to the phone, per my understanding) so they do not appear on my iMac.

I repaired permissions per the process you linked. That fixed My Photo Stream in MacOS Photos app. I confirmed again that photos taken on my iPhone do not migrate to My Photo Stream on my phone and hence they don't appear there in the iMac Photos app. I downloaded the photos manually (including some shots taken after the permissions update and reboot) and confirmed they are jpegs. The phone is on the same wifi network as the iMac and has a fully charged battery and has My Photo Stream enabled in iCloud section of the phone's Settings. So that is still a problem and has been for months (on and off).

So I set Photos format on the phone to normal (not HEIC) and they still do not show up in Photos on iMac or Photostream in iPhone Photos. Something is wrong on the server side.