Anyone run into sand flies & have a preferred repellent and bite remedy?

Prepping for another trip. Last couple times in the Caribbean, my partner ran into issues with a biting insect and believe it was from sand flies. Possibly could be some other bug as we never saw them flying around & she didn’t feel them biting. Guessing she encountered them at the beach but maybe they were hanging out on the grasses/gardens around the resort. Oddly enough, I didn’t get a bite & some other women at the resort were also complaining but men weren’t – lucky us! I don’t think this is a resort or a specific island issue but a reality of bugs on any Caribbean island.

She tried a strong deet bug spray and that didn’t seem to work – maybe it preventing more bites & the damage was done, hard to tell. To help with the itching, she purchased a cooling cream which kinda helped but not great. Thankfully (in a way), the bites flared up later in the week which allowed for a few days of fun, but it did make for an uncomfortable last couple of days & flight home – and a few days after too.

Seems like there are many folks claiming repellents and remedies that work – but I’m a bit skeptical on many of them though.

Has anyone have recommendations that have proven to work? Thanks!!