Why is my second sim still connecting and using cellular data if the other sim is picked for cellular data?

Hello.

I recently received an eSim as I recently moved to Germany.

I still have my Sim from Verizon in my phone, as I'd like to keep my American number tied to my phone.

In the Cellular Data setting, I have selected Telekom, the german provider. I have turned allow cellular data switching to off, default voice line to telekom.

However, if I go into the Verizon sim tab settings and turn the line on, it still tries to connect to a network. I see two cellular indicators in the top right of my device.

Why is this happening? Is there a way to keep both lines turned on, but only allow one to connect to cellular data? I would think this is what the Cellular Data menu option would do, but that seems to not be the case.

Thanks