morradi I've figured out the issue as to why Star Alliance award searches keep redirecting back to the start page. It's very much on the Turkish Airlines software engineers for being dumb and having this bug in production for so long.

When you press search on the Star Alliance award page, as soon as the URL changes to something like

turkishairlines.com/en-us/miles-and-smiles/account/book-star-award-tickets/availability/?cId=eb48fa30-4f7a-4d5b-8c3c-4e04b9bbc862

You'll want to double-click the URL bar and select the URL so you can copy it. This might take a couple of tries in case you can't get the URL before it redirects, but keep searching until you get the URL.

Once you get the URL, you'll want to remove the slash between "availability" and "?cId=". That slash actually shouldn't be there, and messes up the request to Turkish's backend to see star alliance award availability. After removing that slash and pressing enter, you'll be able to see availability.

Then you should be able to ahead and purchase, but there's a couple of bugs that they haven't figured out:

For some reason when booking a ticket, I couldn't use a credit card to pay the fees since there was no purchase button. I ended up finding a Reddit that stated that Venmo works for paying taxes and fees. I did that.

Also, the confirmation page does not work because of the same slash issue that messed up the Star Alliance award availability search. Amazing how great Turkish Airlines' software engineers and IT is. The confirmation URL won't work if you remove the slash, so I ended up just finding the flight I booked under "My Flights" in my Turkish account.

One other quirk - I used my Turkish miles the other day to book a United first class ticket. Turkish's "My Flights" page said I booked an economy ticket (even though their emails stated I made a business class redemption). Thankfully, United's end says first class. But something to be aware of since I'm not sure if that is also wrong on other partners.