Considering the Russians have been preparing for some time. It would be extremely strange or worrisome if logistics or reinforcements are already being strained when they barely push that far in.
I just don’t see Putin nor his advisors doing something that risky if logistics or reinforcements weren’t already in place.
It is a fact that the Russian Army has a logistical problem, for you to keep in mind about this, just see that most of the most advanced Russian troops in Ukraine were where the airborne assault took place, the cities close to the border point in all of Russia are still too close to extend the logistical force and have any supply and ammunition problems.
When we actually see hundreds of tanks, IFVs and other vehicles crossing different points of the border, it's really that the logistical force will follow and at that moment there could be some problem with that.
I believe that Putin expected some agreement and a term of surrender from Zelensky, but that is clearly out of the question. Zelensky has already signed the total mobilization order, distributed 10,000 rifles to the people of Kiev and is calling on everyone to resist the Russian invasion.
I really hope that the second wave will mobilize more than half of the resources that the Russians have deployed on the border. That first wave, and even, according to intelligence claims, the Russians only employed 1/3 of the entire force near the border.
In Belgorod alone, for example, there are thousands of troops awaiting an order. I saw some logistics trucks in Belarus approaching the border. Among other moves.