Creating blocks on localhost was not a problem, everything was displayed both on the wp-admin side and on the frontend side (created on Linux, PHP 7.219, nginx)
After installing for test on Windows + the latest XAMPP (PHP 7.39, apache) , it turned out that the blocks do not render (they can not be seen both on the wp-admin and the frontend site).
That’s why I put it on Raspberri Pi (PHP 7.120, apache) and it started normally. I thought maybe it was a matter of Windows and some server settings. However, when installed on a normal web server (Linux, PHP 7.0.33, apache) also did not work.
Does anyone have an idea what could be the reason for the blocks not being rendered?
In the following function does not enter callback at all (text_block_render_callback), however register block works.