The Donetsk People's Republic and the Luhansk People's Republic, fighting alongside Russia against Ukraine, have been recognized as independent states by Russia, Syria, and North Korea (as well as by Abkhazia and South Ossetia, as pointed out in the comments below), but I'm struggling to find any information about the mutual recognition of those two territories as independent states. In particular, I can't find the names of their ambassadors to each other, while I was able to find the names of their ambassadors to Russia.
I'm highly puzzled by the apparent absence of any information about the mutual recognition of Donetsk and Luhansk, given the ties between the populations of those two territories and them bordering each other and being allies in a military conflict.
Have Donetsk and Luhansk recognized each other as independent states at all? Have they established mutual diplomatic relations? Have they exchanged ambassadors? If not, why? Do they have a problem with each other?