I didn't find any system plugin or other component or a strange combination of settings in HikaShop. So I went in the config and changed the session handler to none instead of database as I remembered that on some servers, that could cause problems. I then tried again to use the account This email address is being protected from spambots. You need JavaScript enabled to view it. and now I don't have the problem either with that account. So it seems to be solved. Could you try on your end and let me know if you still have problems ?