On the site page is a component of the Bitrix Photo Gallery 2.0, CNC included. The link of type / # SECTION_ID # / - works fine (the component automatically substitutes the album id when outputting on the site). And if you replace the CNC setting for / # SECTION_CODE # / for Album, then the section code, namely "/ # SECTION_CODE # /", is displayed in the URL.
I googled this question and found that I was not the first to come across this problem, and, like, Photo Gallery 2.0 does not support SECTION_CODE. But somehow the issue should be solved with the support of the CNC, because it is stated in the component options. How to display something human-readable in url instead of ID for album pages?
Updated. Bitrix technical support response: unfortunately, SECTION_CODE is currently not supported in the gallery. Implementation costs in terms of work.