And make sure to include your grid when you define a station location in the TQSL program! Otherwise you get confirmation for the QSO, but it is useless toward a VUCC award. Multi-grid QTHs work fine in LOTW, too.
It is important to note that if you have operated from a single location covering more than one grid (i.e. a 2 or 4-way grid boundary), you should upgrade your TQSL configuration file. You do this by logging into LotW, going to "Your Certificates" and clicking on the "Download current TQSL Configuration file." Even if you downloaded the "latest" TQSL, you may still need to perform this update.
If you create a TQSL "Station location" containing more than one grid (seperated by a comma and space,) your grids beyond the first grid may get depreciated. Several stations, including myself, have witnessed this behaviour. To test it, go create a new station location with two grids. Example: "DM00, DM01" Save that station location. Go back into it and see if both grids appear. If only the DM00 grid appears, you need to update your TQSL Configuration file per instructions in above paragraph.
73 Clayton W5PFG