warmd hogging processor 100%

About 90 seconds after re-booting my iMac, logging in, logging in to my mail server and reading my first email, everything on my screen - except the pointer - froze.

I tried closing the browser tab, then the browser, then initiating Activity Monitor, then logging out, then closing down... Nothing worked. The screen was frozen.

I fired up my laptop when my iMac came back to life. My buffered series of click-commands were executed one-by-one. The Activity Monitor popped up and showed warmd hogging the CPU 100%.

Within a few more seconds it disappeared from Activity Monitor's list of processes and everything returned to normal.

warmd has never done this to me before.

I read that it is supposed to pre-load the cache with commonly used applications... ironically to increase speed of response, but it stopped me dead.

Is this a bug with Mojave (10.14.6)?