RHEL9 text mode installation: GPT and ext4 - manual partition layout question

Dear community,

I’m in a situation where I need to use the text installation method of RHEL9. I cannot use XFS which prevents me from letting RHEL do all this automatically for me since I do not have the option to choose ext4 then.

I manually set up GPT and partitioned /dev/vda using the command parted -a optimal (sizes defined using percentages). I also set up the flags and mountpoints, please have a look at the attachments for details.

The text installation menu says "Error checking storage configuration".

I already read a lot of RHEL docs and other sources which provide a great general overview and made me hopeful to find a trial&error solution but whatever I tried did not do the trick.

Can someone help? Which conceptual mistakes do I have in my configuration (see attachments)?
Thanks