Summary
Central UI language does not change to English if Central was installed with Japanese as a supported language in older versions of 10.x
Error
As written in Central User Guide, Central UI language on a browser is able to be changed automatically depending on the language preference of the browser even if Central is installed with non-English language in addition to English.
However, in at least 10.20 and 10.22, the UI language does not change to English even if the language preference in a browser is set to English, if Central was installed with Japanese in in addition to English.
However, in at least 10.20 and 10.22, the UI language does not change to English even if the language preference in a browser is set to English, if Central was installed with Japanese in in addition to English.
Cause
It is a known behavior and it is highly recommended to upgrade to a newer version than 10.50 which work fine as expected.
Fix
It is highly recommended to upgrade to a newer version than 10.50 which work fine as expected.