I want to pair 2 Victron multiplus 2

Victron Multiplus 2. Parallel operation SN#2351 old, SN#2609 new. The old one made in India then new made in China, is there a way that they will pair correctly?

The full details can be read here

But the main point is, that you need matching compatibility IDs.

I dont know what the numbers you posted mean, since they are neither serial numbers nor firmware IDs nor comp IDs.

A serial number would be HQ123456789
A firmware ID would be 2623556
A comp ID would be 2623_A

With older units its possible that theres no comp ID yet, so the first four numbers of the firmware ID count (2623 in this case). Since there never was a 2351 version i guess your numbers are not parts of the firmware IDs

I will have to check the new one firmware and ID,
I’m not home right now since yesterday late. Thanks for your help

Post the model number as well, the PMP-like number.
I suspect you are out of luck, 3 years is a bit of a gap, even purely from a wear and tear affecting symmetry perspective.