I forgot to mention in my earlier post that my router models are RT-AC88U and they are affected by this. This is obviously a widespread issue impacting a large amount of their models.
I'm experiencing the same issue here all day today. Getting "no space left on device" in the logs. I ssh'd to the router and see that the "asd" process is spiking. I did a full factory reset, same problem. I'm not wanting to flash with outdated firmw...