The anxiety of Putin is justified. As I explained in the past I am working in the oil industry for over two decades and I also worked in Russia, in this precise area as well. In this area is a very big fuel distribution centre. When I was there they told me it's the biggest in Europe, but I don't really know if it is. It's huge, anyway.
More important, an important gas pipeline junction is there. Some 40-50% of all former western gas was going thru this and Hungary and partly Slovakia are getting it's gas this way, still. To make it even more entertaining, as far as I remember there is also a pipeline going south from there, connecting Turkiye and some other countries in the south of Russia.
There is a general rule in war. Don't cause the enemy problems, create dilemmas instead. For problems there is a solution, dilemmas only have a choice between multiple bad outcomes. I will come back to this later.
Ukraine could already cut the transport of Russian gas via it's pipelines to Hungary, but didn't do not to anger the Western partners.
It must be painful for Ukraine to let this gas thru knowing the money Russia makes with it is used to pay for the war against them self. Ukraine had a dilemma here, but now they solved it. Let me explain.
Russia's dilemma now is hard, very hard. The way the Russian army fight is simple: Destroy everything in front with artillery and bombs, then send in infantry and tanks to handle the remaining resistance. Russia doesn't care much about people, no matter their own or others, but they care about their oil and gas. To start a counter attack means this will be destroyed and Russia doesn't has enough trained soldiers and other means anymore to handle the situation different.
The dilemma is choose between two similar bad options. Fight Ukraine and risk the destruction of this vital facilities Russia cannot replace or even fix due to sanctions. It would also cut off it's only remaining allies in the west (Hungary, Slovakia) three months before winter and lose the income, too. I am not sure if the south of Russia, Turkiye and Georgia would also be cut off completely or if there are alternative routes or options like the use of tankers. It would be difficult and expensive, anyway.
The other choice Russia has is to accept the presence of the Ukrainian Army in this area and risk further expansion of the occupied areas. This is hard to accept for Russian people who still believe the Russian army is strong. They know if peace talks start this will be a strong talking point for Ukraine and Russia will have to make a lot of concessions to get back control.