Hello and welcome to the Flow forum.
It is very difficult to know what you are seeing from this description. It would be incredibly helpful to have a photo of the capped surface of the frame. It is perfectly normal for bees to leave the edges of frames uncapped, so depending on what you are looking at, it could be fine, or it could prove a problem for harvesting.
By the way, in SoCal, most people take their last harvest in the beginning of July. The summer is so dry, that even if there are flowers, they don’t produce much nectar after that. As you have found out, if you don’t harvest in July, the bees may use it all up. Hopefully you have 2 brood boxes under your Flow super, so that they have enough stores for winter. If not, you will need to plan to feed. I would take the Flow super off now if it is empty. Once the nectar stops, the propolis starts, and you really don’t want propolis in the mechanism of your Flow frames!
Sorry I couldn’t answer sooner. Our house is being tented for termites on Monday, and I have spent the last 14 hours bagging food and preparing the area around the house for the tarps…