The gap in the turret IS the issue.
Most notably the overhang of the turret cokmbined with the gap. Shrapnel, debris from moving through obstructions, etc. are going to be an issue, especially while in transverse since things can catch the bottom of the overhanging turret and be dragged into the tighter space between the main body and teh turret as it transverses back.
The skirting issue is 2 fold.
The first is that the back appears to have a different skirting configuration than the front, with a much longer skirt over the tread than is true in the front. It has also been squared off instead of angled as it is in the front. While this is good for treat protection (voering more tread with the skirt), it creates movement problems in uneven or boggy terrain when operating in reverse.
Second, the skirting is too squared off. There is no deflection angle in the skirting. This means you are either going to have to go with VERY heavy skirting in order to protect the treads, or you might as well leave the skirting off since it is vulnerable to even low-grade weapons like a LAW that could penetrate the skirting more easilly since the rounds can hit 'square" and penetrate to damage the treads beneath. If you add a deflection angle, you reduce the force of impacts on the skirting by an order of magnitude, increasing your tread protection at no cost of weight.
Lastly, following up on the transverse overhang… Imagine a simple IED going off next to the tank while the turret is transversed and the underside of the turret is exposed to the ground below… Explosive force going UP and hitting what is certain to be a very thinly armored portion of the vehicle. I’d call this an Achilles Heel on the modern battlefield.
Angle the skirting
Re-engineer the rear skirting to allow for reverse movement in rough terrain (same config you used in the front would work)
Shorten the turret to elliminate the transverse overhang issue