"Grid MORA" Different Navigraph - SkyVector.com

I’m currently working with “Grid MORA” and I noticed that the values for Navigraph (same as LittleNavmap) and https://skyvector.com/ (same as Aivlasoft EFB2) are different.
it’s not just the classification but also the values. If I take the highest number in the four fields with skyvector, I don’t get the same value as with Navigraph. For example, on the right from LEBL to LEGE the highest value for skyvector is 6.5 and Navigraph gives 7.6.
What is true and why?
Thank you very much for the clarification

MORA values are generally not provided in government source an are calculated by the data supplier. There are, however, some governments that do provide off route altitude data and a data supplier may elect to use the government source values in their data services.

So, without knowing what data provider SkyVector is using, I would say both are correct so far. Possible that the Jeppesen calculated values are a little bit more higher, but better higher than to low. Again, there are several sources available and GridMora is not a source what the government will offer - so you can use 3rd party sources or as in our case, our data supplier calculates it.

Hope that helps

Thank you for the detailed feedback.
Then is this also the case in “real” life, that every chart application shows different values?