I have an advancement completion date on one of our scouts, Jayden Lamb, that was entered incorrectly and I cannot remove it either on the web-based trooptrack or in the app. We are in Troop 58.
Just tried it on my desktop in Chrome and it worked fine. The “Clear” button would not work in Safari on an iPad or in the mobile apps.
This seems like an iOS issue. Rather than giving you a keyboard you are only presented with date picker scrollable Month Day Year options. There is a Clear option but it does not remove the date text from the field.