2 mongo instance down when i change priority

We are using replica set with 5 member. (1 primary 1 arbiter 3 secondary).
Our 3 mongo members are working in the same place (PSA) as the application.
2 mongo members are working another side (SS). So we are using replicaset with members in multiple locations.

Data bearing nodes priority are 20 - 15 - 10 - 10.

When i change the priority 15 to 20 with this document https://www.mongodb.com/docs/manual/tutorial/adjust-replica-set-member-priority/, 2 mongo instance closed and didn’t open. always trying to restore but no result. Always restarting.

I started a initial sync for 1 node but it is very slow. What can i do ?

Could someone please help me ?