So it looks like the numbers 264 and 265 are ignored if they are not inside the supported SxxEyy season/episode number pattern.
The reason for this are of course the codenames of the video codecs H.264 (AVC) and H.265 (HEVC).
Many users include these into their filenames. So in an extremely unlucky case it could happen that all episodes would be recognized as episodes number 264/265.
To prevent that the above rule was incorporated into the scanner.
The only solution for seasons with such high episode counts is to use the officially supported naming style.
There is software which can help you with renaming. Filebot and Tiny Media Manager are a few examples.
