I purchased a 2x8GB Crucial kit CT2K8G3S186DM based on my research online. I received 2 sticks with ct8g3s186dm.m16fp printed on them.

I'm getting the blinking blue light on boot up. Still debugging the issue.

According to this Reddit thread, apparently it's no longer supported.

The thread suggested I use HyperX Impact HX318LS11IBK2/16 Memory 1866 MHz DDR3L CL11 SODIMM 1.35 V, 16 GB Kit (2x8 GB) instead. I ordered those.

I've installed the HX318LS11IBK2 RAM, and surprise surprise, not booting after 10-15 minutes. I tried reducing to a single stick of 8GB and it still refuses to boot 8 minutes later.

All posts relating to upgrading the RAM in this unit seem to be old. Something must have changed...

Via this megathread I've found this searchable compatibility doc. I contributed my findings to the form.