The suggested values in the aspect-ratio dropdown contain invalid css values. The correct format is either a decimal (e.g. 1.7) or a division (e.g. 16 / 9). The current suggested values are in the format “X:Y” (e.g. 16:9).
Step-by-step reproduction instructions:
Open the Post Editor/Site Editor
Select a block
Open the Design > Sizing area in the property inspector
Got you, I really missed that part. So many little things changed recently.
This is a welcome addition for the applicable properties.
I think @T-low brought that up here some time ago.
Hopefully, in case it makes sense, this can be extended to other properties in the future.