Science advisor problem

[Der PH]

Since I installed the 1.21 patch, I have a little problem with my science advisor.
In my little mod (made with version 1.16) I made some changes to the tech tree (mainly to get frigates and galleons earlier and ironclads a little later). It worked quite good with version 1.16, but after installing 1.21 the connection lines from the original tech tree appear and do not at all match to my modified tech tree. It's only a graphics problem, my mod still works, but it's a little annoying that the lines in the advisor screen are not connecting the techs properly.
Anyone else got this little problem?

[Der PH]

Here it is.

I made most of the tech tree changes in the medieval age. I rearranged magnetism, physics, metallurgy and a lot of other techs.

Using version 1.16 the rearranged techs were connected by straight lines. This did not look as well as the original connecting lines, but at least it was correct.