Thanks so much for suggesting the layout workaround. In a pinch, it does allow us to edit and update so thank you. Unfortunately, it is also completely cumbersome. If I want to add a new element into these containers, I essentially need to create a “dummy” section for dragging in new elements, and them move them around in the layout tab. This presents a stumbling block because if we don’t want to continue editing in this workaround way, it means essentially rebuilding an entire site by manually converting every classic container. We built our website when classic containers were the only option!
So, per @JesperF’s comment on the support response to this issue above, is there still an improvement being worked on to globally migrate all classic (v1) containers/elements to become compatible with drag and drop functionality? Again, thanks so much for ALL of your help!