WordPress Gutenberg (react) automatically changes "class='x'" to "classname='x'" for web components, how to turn it off?

Question

WordPress

I added my own blocks for gutenberg, there are web components (standard ones) in the blocks, but in the WordPress admin panel, a replacement "class='x'" на"classname='x'"for them automatically occurs and this breaks the styles (it looks like a replacement at the js level, I haven’t seen the preg_replace engine for this in php). This does not happen at the front. I suspect that it's in react, that it automatically does this for all components in a row, how can I disable this?