Getting countered mid combo 🤔

I play Kage but his double crouching medium punch will sometimes not connect about 20% of the time, and I’ll end up getting blocked, EXed or CAed. Is there times when it’s not suppose to connect or is it an input problem.
Even if I had a turbo button masher I feel like it won’t connect when it doesn’t.

You need it to be a counter hit. It’s not comboing because crouching strong doesn’t combo.