I am seeing this issue with the below setup.
MC- ASR 1013 running IOS-XE 16.6.5
BR- C3945 running IOS 15.5(3)M9
See the below on the logs on the BRs eventually BR will become unresponsive.
3542040: Jul 18 20:22:15.475: %SYS-3-CPUHOG: Task is running for (2004)msecs, more than (2000)msecs (83/19),process = OER Border Router.
3542041: -Traceback= 0x405005Cz 0x4019510z 0x403C458z 0x400DD74z 0xB643B8Cz 0x8667780z 0x8667C00z 0x867A370z 0x865BEFCz 0x4F74E84z 0x4F5BDA4z