Club Log's aim by integrating with LoTW is to simplify synchronising QSOs that have been matched (i.e. QSLs), and it's assumed that you will continue to upload your station log ADIFs to Club Log directly.
The database at Logbook of the World stores all QSOs uploaded by you, but there is no method available to edit or delete those QSOs. As a result, when you upload a logbook (ADIF) to LoTW it becomes an irreversible action. The problem with this is that there are regularly situations where a QSO is uploaded but later edited, for example if the date/time was miskeyed or the callsign turns out to be busted. This means that in most LoTW accounts, there will be records that have be edited or even deleted from your own logbook that remain in LoTW.
For these reasons, Club Log only downloads QSLs, not all QSOs you have uploaded to LoTW.