Should never really use any x64 version of Terraria, it was never meant for x64... Terraria never should exceed upwards of 2GB, but I believe tModLoader applies the LargeAddressAware flag to the exe which lets Terraria use up to 4GB but In my experience of installing a lot more mods than you would ever need the game only got up to around 2.5GB...
By using x64 versions of Terraria you're only causing the issues yourself. imo, anything on this board should never support x64 versions..