The Ukrainians have achieved a tactical break-in and have opened a breach.
It appears Russia currently doesn't have either the ground maneuver unit reserves or artillery fires to respond locally and seal this breach in the Russian forward defenses.
It remains to be seen if the Ukrainian military has enough local mobile forces to make this into an operational scale breakthrough offensive that cuts the Russian ground lines of communications to Izyum.
The only rapidly available tool for the Russians appears to be airpower.
The Russians have to commit the VKS in a big way to slow this Ukrainian break-in down and helicopter lift infantry blocking forces in front of the Ukrainians to save their logistical position at Izyum.
People should expect to hear about Russian claims of successful air strikes & Ukrainian claims of VKS jets and helicopters shot down in the next 48 hours….