I think, the WAL recycling on standby names the recycled segments with the latest timelineID (in this case it's 0x10) which creates WALs that there shouldn't have been like 000000100000146A00000001 instead of 0000000F0000146A00000001. This patch recently applied to 9.1.9 (but not in any stable release so far) solves this problem as far as I can see. Try and see if you can patch it: