Workaround for what??? You only stated that there's an issue, but have not shown us your issue. The link works for me. see screenshot

Do you have the same issue with Firefox in Troubleshoot Mode? https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode#w_how-to-start-firefox-in-4troubleshoot-modesf5safe-modesf

This is a screenshot of what I get when I try to accessany Tiktok page...

That's much better!!! What security software are you running?

None.

Even after refreshing firefox I am still getting the same error message - secure connection failed.

Wifi or plugged in? Windows home or pro? Can you try booting to safe mode with networking and try again. Also check your proxy settings. see screenshot

My connection settings don't allow me to select the DNS HTTPS options.

If TikTok won’t load in Firefox, the usual fixes are to clear site data (Settings → Privacy & Security → Cookies & Site Data → Manage Data → remove *tiktok.com*), disable Enhanced Tracking Protection for that site, and temporarily turn off extensions like ad-blockers or privacy filters that often block TikTok scripts. Also make sure Hardware Acceleration is enabled and that Firefox is fully updated. If it still won’t load, try opening the link in a private window or a new Firefox profile—if it works there, something in your main profile (cache, extensions, or settings) is causing the block.

The PR_CONNECT_RESET_ERROR code indicates that the web server or an intermediary -- that might be security software, parental control software, a corporate proxy server, your internet service provider, a protective service the sites uses to block bot attacks, or something else -- sent Firefox the RST code to immediately stop trying to connect.

It can be challenging to track down why Firefox received this code. If you notice a pattern of various sites affected by the RST problem, it could indicate a change on your system, your network, or by your internet service provider. If it's just this one site, hmm, can you load the home page at

https://www.tiktok.com/en/

(or other addresses that do not have all those tracking parameters on them)?