seeing as you had the same issue with two different brands of controlers, I am going to hazard to guress the issue is with something you have set up, and not the controlers for the current issue. a 100 watt pannel is going to send almost nothing to the batteries when you are using the load for your fridge, especialy if it is a 12V fridge and thats how your running it. while it is under the 20amps that load termal can handle it is more than your 100 amp panel puts out.
I went in and looked at my settings for Li and they are optimized for LFP batteries so using the gel setting isn't doing any better, in fact it probably isnt as good. try it with your sectond panel hooked up and if its a bit better I would look at getting a 24V split cell panel and letting the MPPT function realy shine. I have a 325 watt split cell 24V panel and it cranks out the power to the batteries.
Im only guessing at how you have it set up but putting a fridge on the load termanals seams excessive, mine draws 7 to 12 amps on 12v mode which is why I never use it that way.
Steve
