My sweat is creating a stale scent on my clothing

This is kind of hard to explain so bear with me.

I sweat more than a normal person, but not an excessive amount (I think). In the morning I put on a clean shirt and deodorant. As the day goes on, there is a sort of stale scent that comes from my under arms. It does not smell like mildew, or BO. Just sort of stale, almost chemical-like scent.
I cannot figure out what it is. It's almost every day within ~6 hours of me getting dressed. It's stronger if I sweat more, and it's faint if I sweat less.
It's basically guaranteed that I will have this smell by the end of the day. If I have plans after work, I have to make sure I have time to go change or bring a change of shirt. The smell does not seem to stick to my skin, but my clothes. My clothes do not have this smell before I wear them.

For more info, I use Gain classic laundry detergent and oxiclean powder. I use Secret aluminum free clear deodorant in the ocean breeze (?) scent. I shower every day.

Please help lol