"Select Listing" for a sale is not working

[DragoninKnots]

This issue has been going on for a while. When I'm setting up a sale and want to select listings for that sale, the words I type in the "Search for a specific listing" box disappear on me before yielding any results. I can search for one letter but not two or more letters. It's inconsistent. Sometimes it will miraculously work. Most of the time not.

[NanaLetha]

Are they all in the same shop section?

[DragoninKnots]

No, I was trying to search by theme.

I finally got it to work, but it took a long time. It's a struggle every time I set up a sale.