So the error in your main.log occurs here:
[info] [cleanUpInstallers] Removing wordpress installers
[error] Error: Encountered an error: RangeError [ERR_CHILD_PROCESS_STDIO_MAXBUFFER]: stderr maxBuffer length exceeded
I asked our Developers and they proposed going to ~/DevKinsta/wp and making sure everything in that directory is deleted. Is DevKinsta able to repopulate that directory when you try to create a site again?
Here are some screenshots of how that directory looks for me
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You may just have to try unzipping the WordPress directories into folders if nothing else works.
Please let me know if nothing works here. I don’t think anyone else has had this exact error so it’s very unique.