Rheinmetall recently announced that they were starting up a facility in Ukraine.

https://www.cnn.com/2023/07/10/business/rheinmetall-german-tank-factory-ukraine/index.html

Rheinmetall will open an armored vehicle plant in Ukraine within the next 12 weeks, shrugging off concerns other Western defense companies reportedly have about building a presence in the country while it is at war with Russia.

I am guessing that the factor is more that Ukraine's considered to have a decent-enough air-defense situation now that it's reasonable to start operating factories without worrying about them getting hit with missiles or something.