I had this issue earlier, so thought of noting it down here 🙂
Issue: When workflow task is received, the URL of approval link still pointing to old URL even after setting Alternate Access Mapping (AAM). There are two things I did, they are as follows:
- Set the new URL as default in AAM
- Republish workflow from SPD, make sure SPD is connected with new URL defined in AAM.
- Optional: Do iisreset