get another ferret
am not trying to be funny, but asking a single ferret to bolt rabbits, is in my eye's asking alot, ferrets by nature are socialble and should be kept in two's or more, if you havent been ferreting in a while, that could be your problem, also Ive always found, if one ferrets darts down the hole, others will follow, or as already stated, maybe the fert know's better than you,
last week, we ferreted a warren that I would have bet £100 on, that we'd get loads from, we got one, yet a bit further along, on a sorry looking warren, we had bolts/digs, and lots of blooded ferts