SELECT * FROM Table1 WHERE OneDate = #31/08/2020#
works perfectly in Access sw, raises an error in b4j using ucanaccess library.
I just tried this in Access. In the SQL View (where you can type/see the raw SQL), I pasted the above statement. Running the SQL works and (presumably) returns the desired result. But, here it gets interesting, when you switch to the Design View, the Criteria field shows #8/31/2020#
So it looks like Access may actually not sent your query as it is typed out to the underlying DB, but change the date to #8/31/2020# before executing the query.