Have I hit iCloud Folder Sharing Limits?

I have the 2TB iCloud plan. I have approximately 150GB of family photos stored, taken across the last 20 years.

I want to share these with my wife so I tried to create a sharing link for the folder. This initially failed, so I broke down the folder into 3 x 50GB sub-folders.

I shared the first one just fine, but when I tried to share the others I hit an issue where the sharing initially appeared to work, but after about 10 seconds the 'Shared by Me' status disappeared and also the link no longer worked.

I can't get past this whatever I try. Is there an overall sharing limit for iCloud that I may have hit? Given I have 2TB of storage it would be ridiculous if I couldn't share any more than 50GB...

For context, my wife also has an iCloud account (her own) with 200GB of storage. I used her email address during the folder share process (the same one linked to her Apple ID) if that makes any difference.

Any ideas?