You need to hand-pollinate the blooms, according to crfg.org.

Hand pollination is the best way to ensure large full fruits. One caveat: Some Passiflora are not self-compatible, and need a different clone to pollinate it. This may be your problem more than the lack of vectors.

Yellow passion fruit is not self-fertile. I have the same problem. Do you still have flowers? Then we could share some pollen and get our plants to set fruit.

I grow yellow passion fruit (Maracuja- Brazilian variety) and I have three vines growing next to each other. I also cross hand pollinate the flowers. Look what I get! My record is a 430 grams, almost a 1 lb fruit.

Last year I did not have bees either and thankfully hand pollinating my purple colored passion fruit flowers took the place of bees. I used a Q-tip and had a huge crop.

I didn't know that the yellow variety are not self fertile, bummer there.

BTW,

I solved my bee problem by going to Lowes and Home Depot and watching the bees on the perennial flower patch to see what they liked. I wound up with four varieties, and
between them, my carambola, calamondin and Kumquats the bees found my property and now do the job God meant them (and not me) to do :-)

Some cultivars of P. edulis flavicarpa are self incompatible, but many are not. Hand pollinate right as the flowers open for best results, pull off an anther and use it as the applicator on the ends of the three stigmas. You'll know in a few days if it works. Paul

Just go round the vine with a paint brush and swish the brush over the flowers - that will pollinate the flowers for you. Luckily not necessary for me to do - but it does work. Cheers. Royce.