A traceroute that bounces between two routers

Last week the branch team removed VLAN 20 (10.50.20.0/24) from branch router R1 when its old servers were retired. Since then the WAN link between HQ core router R2 and R1 runs noticeably busier, and a monitoring check that still polls 10.50.20.5 reports "TTL expired in transit". The branch owns 10.50.0.0/16. R2 reaches it with one static route. R1 uses a default route to R2 for everything else. The WAN link is 10.0.12.0/30: R2 is .1, R1 is .2, and one-way delay is about 2 ms.