Just to be sure, you should check whether SSHD is enabled: sudo systemctl status sshd.service
If you never enabled it and it’s disabled+inactive, then no need to reinstall Tumbleweed per the current guidance. Also you can double check your version of xz to make sure it’s downgraded, the downgraded version for Tumbleweed should look like this:
sudo zypper search -vi xz
Loading repository data...
Reading installed packages...
S | Name | Type | Version | Arch | Repository
---+------+---------+-----------------------+--------+------------------
i+ | xz | package | 5.6.1.revertto5.4-3.2 | x86_64 | update-tumbleweed
name: xz
I use Lyx with a local Texlive install, and it works great (openSUSE tumbleweed)