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
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.