PR release strategy being reset due to exchange rate

Hi Expert,

Our release strategy classification is maintained in USD

PR created in currency RMB

Example the PR is require 2 approval level.

1st level is approved on today.

Then when 2nd level try to approve few days later,it will cancel current release and re-trigger new release strategy ( PR value change due to exchange rate from RMB to USD )

User didn't make any changes on pr price,why system will recheck the value again?Is this standard behavior?

Is it possible to lock the exchange rate based on creation date,unless user make some changes on PR price only will recheck the current exchange rate?

Thank you