I had the same problem cloning Olivero. There was a mismatch in the naming of the PreRender class. Sounds like you may have run into the same problem cloning Claro.
https://github.com/mherchel/olivero-subtheme/issues/1#issuecomment-16052...
I believe my subtheme settings had the wrong type when I initially installed and set the new subtheme as default.
Correcting the type after the fact also requires uninstalling the subtheme and parent theme, then install again and I was able to save settings.
Otherwise you will continue to see the memory exhaustion, even with the correct settings file.