Could you please confirm the Studio version you are on.
Do you see the .pvz file in the Resources in the left pane. Does the .pvz file gets removed from the resources too after save?
Try adding the file to resources first then press save and then try to use it in your project.
I noticed this comportment in the previous version but it still occur in 1.9
Yes, the pvz file is still available in the ressources after the save (all pvz are still there btw - std, low, med, high). So are the pvi files.
always load them first then use them.
To make sure, i just tried again : i loaded all the ressources first, then saved, then used them, then saved again.
Again, the pvi disapear from the sequence url entry field and it's not available anymore to be selected.
If i publish it straight after finishing the setup, in 1.9, the published experience can play the sequence but the pvi file has disapeared from the entry field.
Could you please remove the uploaded .pvi files and then choose the Sequence URL from the dropdown. The associated .pvi files shows in the dropdown without uploading it in resources. It seems that some name conflict occurs on adding the same .pvi files manually.
I hope it help.