Install K-Lite Codec Pack Mega (Windows) or use IINA (Mac). For Android, MX Player with custom codec (ARMv7 NEON) is essential.
If this sounds familiar, proceed to the fix. Game Of Thrones Season 1 Dual Audio Fix
Or use GUI:
Right-click the video while playing and look for the "Audio" or "Audio Track" menu to choose between "Track 1" (English) and "Track 2" (Dubbed). Install K-Lite Codec Pack Mega (Windows) or use IINA (Mac)
As HBO moved on to Season 2 and beyond, the encoding standards improved, and the issue largely disappeared in subsequent seasons. But Season 1 remained a thorn in the side of archivists and international fans. the encoding standards improved
C) Fix variable drift (sample-rate mismatch)
A: Streaming apps usually have proper dual audio built-in (just change the language in settings). This fix is for downloaded/local files only.