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As @DCContrarian and @ethicalpaul have stated, the gpm from the well for geothermal is related to the heat added or rejected. Exactly the same equation as standard hydronics. Any refrigeration problems with the condenser or pressures or all that magic will have nothing to do with it.

It would, though, be worth checking what your water intake and discharge temperatures are. You really don't want to freeze that drain field or the piping to it…. and, oddly, you don't want to cook it either. Discharge water temperatures much over 80 F will sterilize the soil in and over the drain field, which is not good.

2.2 gpm per ton is a temperature change of 11F.

1 gpm per ton is a temperature change of 24F.

For heating, in many places that 24F drop would freeze up. Even at 2.2 gpm your source water can't be below 43F or you risk freezing.

Is this system a water furnace? How deep is the well, how far away is the dump point?

Check the gas pressure first before you do anything.

The well water is going to be cold 52 degrees or less so please keep that in mind when looking at the whole picture.

I guess you could flush the exchanger with strong vinegar and see how much build up is in it, you may very well have no restriction of flow.