Reported here:
https://community.aseprite.org/t/using-dialog-show-with-bounds-disables-interaction/27748
Testing this script:
local dialog = Dialog("Test")
dialog:button{ text="OK", onclick=function() app.alert "It works" end }
dialog:show{wait = false, autoscrollbars = true}
local b = dialog.bounds
dialog:close()
dialog:show{wait = false, bounds = b, autoscrollbars = true}
Only with multiple windows:

Reported here:
https://community.aseprite.org/t/using-dialog-show-with-bounds-disables-interaction/27748
Testing this script:
Only with multiple windows: