I think I had to watch "Black Friday" like three times to figure out how Prowl and co. end up in Dinobot Island before Optimus and Bumblebee (and this version, Bulkhead since, well, Prowl isn't with them) got here.
There was one scene in the episode where BA suddenly goes up to Optimus and tells him to retrieve a Genetic Modifier. There was no scene in-between her and Meltdown discussing this missing link to returning her full metallic state. Hence, this takes place before that particular scene between her and Optimus.
The stupid "Tip-Toe" I added because I think I drew them sneaking away badly. Prowl, you're ninja "mastery" is showing.