I am developing custom theme based on underscores and gutenberg block plugins based on @wordpress/create-block. Suddenly, I observed slowdown in server response, it went from ~400 ms to ~750 ms. I disabled all plugins, which are only three (including mine) with no speed difference. I optimised database. I also inspected xdebug profile file and found that large portion of time is spent on loading WordPress .mo default language files. I disabled loading of language files of theme and my plugin.

I also tried disabling xdebug module on server, but without significant impact. What else could I do to get previous loading speed?

I am working on local stack, "WAMP.Net"