So I tried to recreate the Tabaxi and the Tortle races, the Tabaxi one sees to work fine, but when I try to make a character using the Tortle race I made, I get the beholder error message when I go to view my character sheet, and messages saying I can't share the race because it's too similar to the official Tortle race?

Yes, the policy goes like this: you can create any content you want for private use, but you can't publish content too similar to official material.

I don't want to publish anything, I would just like to create a homebrew copy of the official Tortle race for my own personal character building, without having to pay for the official version.

I successfully made the Tortle race and used it to build my character without a problem, but when I go to view the "what's next" step, or my character sheet, I get the Beholder error message.

If I edit the character and choose a different race, I can complete the character creation, but when I change it back to my homebrew Tortle, I still get the error message when I go to view the character sheet, so the problem that's causing the Beholder error message to appear is clearly linked in some way to the homebrew Tortle I made.

I thought it must be because my Tortle is exactly the same as the official version. Is it possible I just messed up somewhere when entering the traits for the race, in a way that doesn't make sense to the program?

Ok, solved my own problem.

It didn't like what I did with the natural armor trait.  Redid the trait and now it's allowing me to use my Tortle :)