Seems like the convoy got lost and ended up in enemy territory.
Kharkiv was one of the most pro Russian regions left in Ukraine, they even had their own "Peoples Republic". Footage on youtube from there on youtube over the last few years makes it look like an occupied zone.Kharkiv has been giving Russia a hard fight
"According to a senior defense official, the US has indications that the Russians are increasingly frustrated by their lack of progress particularly in the north around Kyiv and Kharkiv. “The frustration seems to be predominantly from a stiff Ukrainian resistance.” @ckubeNBC"
The Ukrainian units there are probably the most experienced. Most of the Russian losses seem to be coming from that region.