You own the business as a sole prop and since anything you own/owe is half his, certainly they are entitled to and should have brought your husband into the law suit.
Sorry to have to disagree, but contrary to what you have suggested, the liability of the OP’s husband does not turn on whether or not the OP’s business is a community asset. See
Texas Family Code Title 1. Subchapter B - Chapter 3- Subchapter A - Sections 3. 201 and 3.202
In other words, the mere fact that a spouse’s independently conducted business as defined in
Section 3.202 (b) happens to be community property does not alone render the other spouse personally responsible for its debts.
And if that were true in the case at hand - which it isn’t because the OP’s d/b/a does not qualify under Section 3.202 (b) as being solely managed and controlled by her - THEN the husband would not be a real party in interest and thus not a proper party to any collection lawsuit brought on by a business creditor.
(Noting that we are talking of non-tortiuous claims only.)
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Also strange and unique to Texas community property law is that unless both spouses are liable to the creditors of such an independently managed and controlled d/b/a, the only community assets that are made subject to those debts are the specific assets of the business.
But then other strange and unique things seem to surface out of Texas. Our 43rd President coming immediately to mind.