Per documentation in Create a redirect rule in the dashboard if you create single redirect rule and as per step number 6. you use save as draft it should not deploy this rule. Unfortunatelly it always deploy this rule and automatically enable it. This behaviour is unexpected and with major redirect rule it can harm with new rule enabled immediatelly even with save as draft option.
I do not think it is something with browser. We tested it in Fedora, Ubuntu With Firefox version 129.0.2 and Chromium 127.0.6533.99 an always after clicking on Save As Draft new rule is always enabled. Could it be some other settings in Dashboard that can cause this behavior?