That post has similar info as I asked if you could provide, such as a screenshot showing the issue/error that you are getting. The staff most likely won’t move forward with this until you provide additional info, such as a screenshot showing the error you are receiving. Here, in this post, the OP from the other thread provided a screenshot, and Niantic staff later did look into it.
I also can say that Upgrade Next has caused issues like this in the past. I don’t use Upgrade Next, many due to ML approving the majority of my nomination within 24-48 hours, but also due to the known issues with editing with the option.
Again, can you please provide a screenshot of the error you are receiving? This will be extremely helpful to the staff when resolving this issue.