unable to mine in a mash-up pack

I recently downloaded the greek mythology mash-up pack from the marketplace. Then, today, when I entered my world in creative mode, I wanted to mine some ores in survival, so I switched over to survival to start mining, however, I took like 5 minutes and cannot even mine the deepslate cobblestone, even with haste 2 on me. Could you look into this issue? I would greatly appreciate it