Unable to reset Domain Mapping force SSL https settings

Hello dear WPMU Dev community,

I'm trying to set my first commercial WP multisite network, and I accidentally turned on all force SSL https settings without having a valid SSL in the Domain Mapping settings. This crashed the site and prevented me from logging in.

So, I searched all the documentation on the Domain Mapping plugin. I deleted the plugin files via my hosting file manager and the site works again and I can login again.

However the problem persists. I can still re-install the plugin, but the moment I activate it the site crashes without leaving me the option of turning off those settings! I've tryied a dozen times even with fresh copies of the plugin files.

Please, can anyone tell me how to reset these settings? Probably the settings are located in some file other than the plugin files, because I used unchanged ones.
Do you know what file I should modify to reset the settings? Which lines?

Thank you all for your help,