The library is automatically committing or rollbacking the transaction when the DeleteAll operation is being called with the list of primary keys and transaction object.

The case was reported by Christian Franck of Orsted.

var rowsDeleted = connection.DeleteAll<OutagePeriod>(primaryKeys, transaction);

The author has investigated and it is a single-liner bug in RepoDb. The fix must be done at this line.

Set to 'false' value instead.