Heat distribution on A350

Hi there,
yesterday I checked the heat distribution with an infrared thermometer. I heated the bed to 60°.
In my setting the temperature in the middle of the late reached the 60°. A little less than both sides, like 57°. On the edges in the back the temp. came up to low 50th (51, 52°).
The front side of the bed did not come much over 40°, especially the right side!

Can somebody confirm that, or is my heat bed damaged?!

We have all similar bed heats, it’s a little less difference with enclosure or long preheat.
Thermal insulating the bottom of the bed would also help if you run into issues because of this.

Meanwhile, I changed to an aluminum bed. Temperature distribution is much better now. Unfortunately with the printsheet I’m using on top, autoleveling doesn’t work anymore. But this is a thing I can live with.