Is there a way to edit the percentage chance of getting banglum chunk and what is the correct way to mine banglum ores, ive tried normal diamond pickaxe out of 64 blocks 5 exploded and 0 banglum and a pickaxe with fortune 3 all exploded.

The chance of getting a Banglum Chunk is determined by its loot table. You can tweak this to your liking using a datapack.
Generally the best way to get chunks involves:

1. Not using Fortune. While it does five you more Banglum, it negatively affects your chances of getting chunks (since the ores can explode)
2. Using a Mythril Drill with the Banglum Defuser upgrade
3. Bringing Nether Banglum ores to the overworld. Nether Banglum has a much higher chance to give you a chunk. The explosion chance is directly affected by the dimension the ore is in. However, you can (usually) safely mine it using Silk Touch, which will further help in not exploding the ores