Have your money delivered to your account? If you have not, then have you ever verying your account to be KYC compliance? I have encountered this case in several exchange sites. I deposit my money, it's delivered, but the exchanges didn't credit it due to the KYC problem.
The situation with OP might not be the same as yours, and that he didn't mention his status with HTX. If he has already completed KYC verification procedures or has already completed successful transactions before, or if it is the first time he used the platform. Note that HTX is the old Huobi exchange platform rebranded under a new domain name, and has many accusations including a lost case in court.
My guess is that OP unfortunetly lost his deposit forever because there aren't other valid reasons to a verification case to be pending for 40 years as they responded him. I don't think depositing directly from Polymarket can be flagged by any exchanger since the service is legit.