Cloudflare - Interference

First: Does Cloudflare SSL protection slow down every browser?

Second: My website which uses Cloudflare either will not load properly or will not load at all using Firefox on my linux machine. Both Chrome and Vivaldi will load it correctly on my machine but both say Not Secure. Using Firefox to load my website yields a completely mangled appearance – missing images – the works.

My website loads correctly on my Android Tablet using either the Brave or Firefox Browser.

A Windows machine running chrome in the same house with the same connection will load my site but the SSL padlock icon does not appear there either.

Have my settings been messed with at Cloudflare?

Were you getting the SSL padlock before you added your site to Cloudflare?