If Zoom VDI won't work with Citrix it probably needs to be at a specific version instead of the latest and greatest, which is usually what's in AUR. This doc shows how to modify the AUR PGKBUILD to build the specific version that may work for you.
Figure out your necessary package verison and sub-package version, possibly by looking at the URL for the Windows or Mac version as provided by your firm. This doc assumes you need version 6.0.14 and sub-package version 25360.
First install Citrix with yay -S icaclient. Copy its certs over to your home directory as the instructions say at the end of the install.
mkdir -p $HOME/.ICAClient/cachecp /opt/Citrix/ICAClient/config/{All_Regions,Trusted_Region,Unknown_Region,canonicalization,regions}.ini $HOME/.ICAClient/
Run yay -S zoom-citric-plugin to begin the AUR install process, but quit out at the first prompt instead of proceeding with the install as that would install the latest version, not the one you need.
cd .cache/yay/zoom-citrix-plugin and edit the PKGBUILD file. Modify pkgver and _subver to be the package and sub-package version numbers from above. You also need to update sha512sums which requires downloading the rpm first. Use the URL from source to wget the file after substituting the pkgver and _subver values into the URL. Run sha512sum on the rpm and put the resulting value in sha512sums. Save the PKGBUILD file.
Run makepkg -si and you have the right version installed.
To prevent this version from being updated automatically to the latest edit /etc/pacman.conf and add zoom-citrix-plugin to the IgnorePkg line, uncommenting or adding it if you need to.