No it’s not bad grout work. There is NOTHING that can seal tile. The waterproofing is under the tile and if it wasn’t done correctly then your shower will leak.

Additionally if you are seeing water dripping it means it has been doing it for a long time and there could be mold and rotted wood underneath. The whole thing needs to be torn out and redone

Call a professional tile contractor now and ask for a consult. Is the ceiling below it finished? If so, open it up about 2 ft. radius around the leak area as the damage there will need to be inspected as well. You likely have a failed shower pan which requires that the shower be torn out and completely rebuilt. As cpartist mentioned, grout has nothing to do with it. DO NOT use the shower now as it will only contribute to further potential of damage underneath. Sorry you are dealing with this. It is a major issue and really requires an onsite consult by a real professional.

Is this a shower in a home that you recently bought, a remodel you just had completed, a new-build?

My girlfriend acquired the house recently after her dad passed away i remodeled most of the house but he had already done the bathroom

Sounds like the shower wasn't properly waterproofed or you have a bad shower pan.

Cut that hole and inspect the drain plumbing first. It could just be something Not connected there. Or, it could be a clueless jackofall renovator flubbed up the whole pan, and everything else.

I live in a recently developed area and yes, the grout has allowed leaks in several homes. I think there is an issue with the waterproof board behind but I know some have regrouted and the problem of leaking has stopped.

People mistakenly think that tile, grout and/or "sealers" prevent leaks and waterproof anything. No true. The basic "build" should waterproof the shower. Tile, grout and sealer do NOTHING to waterproof anything.

“Regrouting” a leaking shower pan is a bandaid on a gushing artery. It might stop the bleeding for a tiny moment in time. But it hasn’t fixed any of the real problem.

To be fair it may be a plumbing issue. Mixing valve, diverter etc. Bring in a professional as Dragonfly stated. Don't rip anything out until the plumbing has been eliminated from the possibilities.