I have updated the contact's Mailing country to two-letter name through workflow rule. Besides, I have a process builder that uses mailing country and makes API calls (API call is occur in apex class which is called from process builder). Apex class called from process builder also updates other contact fields.
But sometimes the 'country name' field remains the same - it doesn't update but when I check debug logs that field value is two-letter, and just the user interface doesn't show the update. This issue sometimes appears but in most cases, the flow works as expected. What can be the reason for this unstable behavior?