Problem with machine after installing new X axis

Hello,

I got the old VCE1250 mill from my neighbor with x axis damage.
We replaced the axis with another brand! Later we found out that we got the wrong pitch. The original had 6mm and the new one only 5mm.

With setting the x parameters "Ratio" to the new value for the 5mm pitch the machine worked well so long (1year now)

We use the machine for boring, sleeving v8 cylinder blocks and it worked well. Never had any problem.

Now we invested in new tools to also work on cylinder heads. So now I wanted to use the G13 for milling a pocket in the exhaust valve seat for pressing in an unleaded gas seat ring.
After milling I sadly realized that the pocket is an ellipse. The X dimension is correct but the y isn´t. I don´t speak about hundrets of mm but the x dimension is about 41mm and the y 47.

Now we tried to do the same with the G03 cycle but I got the alarm of different scaling factors.
So I tried to give the X parameter ratio the original value again and G03 worked but my X dimension is about 16% to small (the software things the pitch is 6mm but it is only 5 in reality.

Can anyone help?

How can I adjust the parameters that I can use the 5mm pitch on x and the original 6mm on y?

Thanks in advance.

Bastian