Few things to try before putting them together again:
Put their cages next together, about an inch apart so they cant nip but can sniff through the bars. Its a good sign when the bunnies are laying against the bars together; it means theyre relatively comfortable near one another
The second thing i like to recommend is the decoy tactic. Get a smallish fleece rabbit bed or a fleece dog toy for each rabbit. Leave it in their cages for a few weeks/a month. After those few weeks, swap the beds/toys into the other rabbits cage. They will attack it, hump it, bite it, and get mad that its there. But it helps them get used to having the other rabbit literally right there with them. Once they calm down after a few days, remove the toys/beds (unless they like them)
Third thing is, swap the rabbits cages. Put Diggy into Hitchy’s cage, and visa versa. Swap them back and forth every 2 to 3 days for about 2 weeks or until they dont seem to care about being swapped
These are all “prebonding” bonding tactics. Theyre getting used to eachother without actually being face to face without a barrier. It just helps them get used to seeing, smelling, and being near one another in a general setting. After they seem fine with any/all of these tactics is when you should start face to face in the basket bonding