RT-AC87U 384.5 core 2 high usage

[jpdsc]

Good afternoon,

Since 384.5 my RT-AC87U sometimes has 100% core #2 usage until I reboot it again.
TOP below and screenshot.

Possible cause.
Jul 31 17:59:55 kernel: EXT4-fs (sda1): error count: 32
Jul 31 17:59:55 kernel: EXT4-fs (sda1): initial error at 1521996814: ext4_mb_generate_buddy:717
Jul 31 17:59:55 kernel: EXT4-fs (sda1): last error at 1524165837: ext4_mb_generate_buddy:717

Removed the USB drive and hope this was indeed the issue...

Thanks!