Saving the contribution amounts tab removes the default-iness of the default amount when using fixed amount options. Or editing any price field that is not type text
- On a stock demo install, just save the amounts tab of the "Help Support CiviCRM" contribution page without making any changes.
- The default of "Booster $10" is no longer checked.
This seems to have started in 5.27. Note there is a slight difference between 5.27 and 5.28: In 5.27 clicking the Review button at least does something, whereas in 5.28/5.29 it doesn't.
To upload designs, you'll need to enable LFS. More information