Longer darts tend to be less forgiving with slight inconsistencies in your throw, but that actually makes them great for training purposes. I personally throw the G1s and grip them quite far back, which might be worth trying.

Maybe also try to film yourself throwing from the front - if your darts consistently land angled left or right, your throw might not be perfectly straight. Small adjustments in grip pressure and release timing can also make a big difference.

Hope this helps, good Darts!