FWIW, I have a CT resident with a CA PTE payment. I found no relief for them in the CT OSTC instructions nor regulations.
I then found a Spidell article that listed each state's version of the PTE. This article includes section called "Owner Relief" under CT that states:
Residents and part-year residents may claim an Other State Tax Credit for PEET paid to another state under a “substantially similar” PEET
I searched the CT tax code for their PTE rules and confirmed that is true. Conn. Gen. Stat. §12-699(g)(1)(B)
Each person that is subject to the tax imposed under chapter 229 as a resident or a part-year resident of this state and is a member of an affected business entity shall also be entitled to a credit against the tax imposed under said chapter, other than the tax imposed under section 12-707, for such person's direct and indirect pro rata share of taxes paid to another state of the United States or the District of Columbia, on income of any affected business entity of which such person is a member that is derived therefrom, provided the taxes paid to another state of the United States or the District of Columbia results from a tax that the commissioner determines is substantially similar to the tax imposed under this section. Any such credit shall be calculated in the manner prescribed by the commissioner, which shall be consistent with the provisions of section 12-704.
The moral of the story is don't assume your software knows how to calculate the OSTC when there is a PTE involved. If you don't find what you need in the OSTC rules then also look at that state's PTE rules.