PIPEWIRE OVER RIDES JACK

yes, most distros overrides your previous genuine jackd(bus) for pipewire-jack installation;

you may workaround this and disable the so called "pipewire-jack substitution" by commenting out the substitution rule on /etc/ld.so.conf file, possibly a file under the /etc/ld.so.conf.d/ directory, named like pipewire-jack.conf or else (it varies on distro); for example, here on TW:

/etc/ld.so.conf.d/pipewire-jack-x86_64.conf :
#/usr/lib64/pipewire-0.3/jack/

now run: sudo ldconfig, for the changes to take effect right away; after that you may try to start (genuine) jackd(bus), if still installed or run qjackctl to start it as used to.

now, you'll probably need to do a part or all of that again, whenever the pipewire installation is updated or upgraded; for instance, in my distro I'd always have to re-install the genuine jackd(bus) packages, every time that happens, so you're not alone ;)

re. qjackctl settings being grayed out: yes that's what happens when qjackctl is running as a pure jack client (main display shows "Active") so all parameter settings, besides buffer-size, make no sense as far you can't start the (genuine) jackd(bus) service when in that mode; this is the way that qjackctl runs when under the pipewire-jack substitution: it just can't do anything else but function as a (pure) jack client.

after all and sorry to tell, there is no special "qjackctl for pipewire" version or mode, never was, never will.

hyu.
cheers