Please Help Me Recover My eFootball Account

I play eFootball on my Android mobile device through Google Play, using my KONAMI ID and Google account. Today I started receiving a “Network Error Occurred – An invalid command has been detected. CODE: C_NAJM_0028” message when trying to log in. Even when I managed to open the game once, it logged me out again after about 15 minutes without me doing anything. I recently changed the country/region of my KONAMI account to Japan, and since today I have not been able to stay logged in properly. I already tried restarting my phone, switching between Wi‑Fi and mobile data, and reopening the game. The game opened once but then auto logged out again and went back to the same error, so the problem clearly continues. I contacted KONAMI / eFootball support about this issue, but so far I have not received any response or solution. I would like my account to be permanently reactivated and the login / auto‑logout issue to be fixed so that I can use my eFootball account normally again, without repeated errors and disconnections. I kindly request that my account be checked as soon as possible, the cause of error code C_NAJM_0028 be explained, and my access be fully restored.