السلام عليكم ورحمة الله وبركاته أحسن الله إليكم Right now where I live (Europe) there are some masajid that pray isha around 23:00 and others that pray it at 22:20. Which time is correct and if I pray at the masjid at 22:20 is my salah valid or must I repeat it?

Isha begins when the red twilight has disappeared, and a prayer prayed before its time does not count and is repeated. However, both masjids could be praying at the correct time after the red twilight has disappeared because iqamah times vary from 1 masjid to another.