POS Swap failing with VB a lot

I am running the pos swap with the parameter 'VB' and I am just concerned with how much it is failing. Of 1000 samples, only 82 were successful. Here are some examples of failures:

Failed to get result for ['two', 'child', 'playing', 'in', 'the', 'house'] with transform SwapMultiPOS-VB Failed to get result for ['a', 'goat', 'attacks', 'a', 'man', 'and', 'the', 'man', 'fights', 'back'] with transform SwapMultiPOS-VB Failed to get result for ['a', 'man', 'shows', 'how', 'a', 'video', 'game', 'works'] with transform SwapMultiPOS-VB Failed to get result for ['someone', 'is', 'frying', 'food'] with transform SwapMultiPOS-VB Failed to get result for ['a', 'woman', 'is', 'ripping', 'off', 'a', 'man', 'clothes'] with transform SwapMultiPOS-VB Failed to get result for ['a', 'diver', 'goes', 'underwater'] with transform SwapMultiPOS-VB Failed to get result for ['a', 'young', 'boy', 'rocks', 'out', 'on', 'a', 'guitar'] with transform SwapMultiPOS-VB Failed to get result for ['someone', 'is', 'drawing', 'pictures'] with transform SwapMultiPOS-VB

There are clearly verbs present, so maybe not strict verbs but maybe also including pos like VBG???