The Rod of Lyssa does not provide the player in loot context when generating loot, as the vanilla fishing pole does. This causes loot conditions referencing the player's location to automatically fail when they are called in the fishing/junk/treasure loot pools.

For example, as a pack maker I created a script which replaced the fishing loot pool with one that checked the player's biome and allowed different fish to be caught in different biomes using morelootstuff's in_biome condition. This worked great for the vanilla fishing pole, but caused the rod of lyssa to be unable to catch any of those fish.

Thanks!

Using:
Reliquary 1.3.4.780
Minecraft 1.12.2
Forge 2768

The mod Combustive Fishing by C4 had the same issue, which was just fixed if you'd like to see how he changed his code:

TheIllusiveC4/CombustiveFishing#5