Welcome to the community. 
Please make sure you read the notes for each cheat in the trainer. It states in the trainer itself that you need to disable the durability cheat to be able to kill some animals and bosses, notably the larger ones (bears, sand worms, mammoths, etc).
This is also mentioned in several previous posts in this thread, for example: ICARUS Cheats and Trainer for Steam - #881 by Ravenfyre
This is a game design and there’s nothing WeMod can do about it. The game developers have coded large animals/bosses to share the same hitpoint system as tools and weapons.