According to new legal docs, obtained by TMZ, Austin was arrested and booked last Thursday in Navarro County on an open warrant for his arrest ... which references a grand jury indictment against him with 10 counts of possession of child pornography.

Specifically, Austin (who's 27) was booked into the county jail, posed for this mug, and was released on bond with certain conditions ... including having to submit to random drug testing and other stipulations, like submitting to voluntary searches of his phone and computer. He's also prohibited from viewing pornographic images by any means.

We should note that in docs -- prosecutors cite evidence they say they have including several videos with file names describing children engaged in sex acts that are under the age of 10.

Austin doesn't appear to have been arraigned yet, so he hasn't entered a plea thus far.

It's obviously shocking news -- made even stunning by the fact that the 'Cheer' community there in Navarro -- prominently featured in the Netflix show -- has already been rocked by a child porn scandal ... namely, from one of the stars in the Netflix series, Jerry Harris.

You'll recall ... Jerry was also hit with child porn charges, and he ended up getting convicted in his case -- now, he was hit with a 12-year sentence back in 2022.

At the time, Monica said she was "shattered" by the allegations against Jerry -- noting in a statement, "Our children must be protected from abuse and exploitation, and I'm praying hard for the victims and everyone affected."