I have had two customers contact us that they were unable to checkout on the Etsy mobile app (once last night and once just now.) They are getting a message with an exclamation point icon that says:
"Choose options
Add options"
There are two buttons (Remove and Choose Options) but the customer has already selected the options. The customer from last night was able to place the order when she got home on her laptop. I've contacted Etsy support but wanted to share here in case you run into the same issue. The browser in the computer appears to work but the Etsy app seems to not work. Also, this is not isolated to one of our listing, it is affecting two different listings with different variation sets.