Tor Browser 9.5.4 (Based on Mozilla Firefox 68.12.0ESR) (32-bit)
I have a hundred years old. For months through this mixer changed, there were no problems.
After the output nodes stands VPN - as an extension in the browser - HOXX VPN, Setup VPN, Hotspot Shield VPN
Changed through the white site chipmixer.com (in my old tor browser the onion v3 is not supported, only v2)
In addition to expansion: Adblock Plus, Blockchair. Cookie Quick Manager, Free Adroid Online Emulator APKONLINE, HTTP Header Live, Https Everywhere, Metamask, Noscript, Google Translate, Webrtc Leak Shield
They stood and stand (did not add anything) months, if not years. The browser itself also does not update for certain reasons.
I don't know what caused your problem, but I see several risks in your setup. First: an outdated browser is bad in general, the same goes for using an outdated Tor browser. Adding a VPN takes away the biggest benefit of using Tor: the .onion sites, while adding the risk of them being a compromised exit node.
I don't trust addons in general, and for sure wouldn't use them on Tor. Better safe than sorry.