In the current build (0.82) I can't cast the fishing pole. Clicking doesn't work. Is there something I'm missing or is it a bug?
In vr the controls are a bit different, with trigger being used for reeling in. Can you try doing the cast motion and then release the trigger?
Next update (up tomorrow) will have bugfixes relating to that. Difficult to say if it's going to fix your particular issue though. Let me know if it doesn't and I'll try to figure out something.