This is very reminiscent of what I went through, together with Telcoced who actually solved what is probably your issue as well.
When it comes to booting LUKS with systemd HOOKS, just adjusting the HOOKS is not enough. Read through Telcoced excelent post. It helped a lot back then and now, when applying the current stable update, I was able to boot on first try, no issue at all this time.
In fact, what is described here as ‘broken HOOKS’ is basically how my HOOKS are configured.