IF your in the area i have a few starapple (caimito) you can try
How old was your Caimito before it produced? I bought my two from Mike in 2015 as fairly decent sized 7' trees, and they've barely grown (1.5" caliper) but have flowered but no fruit. OTOH, of two seedlings I started from fruit I got from Mike the same year one is nearly as large as the original two I planted (one green one purple) while another I gave away the owner reported that it's already fruited and has a nearly 4" caliper.
I bought mine from Benders around 2014 from a 3gal.
The first time it fruited was 3 years ago.
Had good production in the last 2 years.
The first two years it was planted hardly anything happened, everything I read said it was supposed to be vigorous.
I raked back the topsoil, applied a bunch of peat moss and a bag or two of mulch and it started to take off. Also been sulfuring the area.
Most people i know grow the seedlings without a problem (except no fruit), i assume the air layered trees might need more attention to get established