Well, here's an update on the temps...

I saw that with my central heating on the temps rose to 27 C / 80 F.
The behavior of my frog changed.

At first Kermit sat in a little bowl in the substrate.

With the new light and heatmat on, I saw that Kermit went almost completely underground, only a little green spec was visible.

I read about this and I concluded that it might be too warm.

I woke up at 4 AM this night and went to check on Kermit. the temps were about 23 C / 73 F.
And was sitting in the bowl like manner again.

I have removed the heat mat under the thank, and I am observing how Kermit reacts now.
I have felt the underside of the enclosure and more surface then expected was heated, more then I intended anyway, so I chose to follow the advice given and remove it.

Currently the temperature is 24 C / 75 F, and Kermit has come up a bit and now sits in the bowl manner again and not completely burrowed down.

I know burrowing is the Natural behavior of these frog species, but I also read I should pay attention to sudden changes in behavior.
The forenamed behavior started when I had the new lamp, and heat mat on and my central heating in my house on.

I have concluded that the notion "every frog is different" certainly applies. And I am leaning towards the idea that Kermit feels more comfortable at this temperature then the hotter temp.

I am not observing any soaking, cleaned some poop so I know there has been eating. There are some crickets left though which have been in there a few days.
I am planning to remove them if they are not eaten soon.

The humidity currently sits between 60 and 70 % but I won't let it fall down lower than 60 %.
The humidity is dropping faster since the new lamp, but that's only logical.
I mist once maybe twice a day.

Can't think of anything more to report lol.

Joey