You didn't mention using the browser cache feature before.
If you are using the browser cache feature correctly, the pages will be pulled from the browser cache. Getting 403 errors, it is either not setup correctly, not used correctly or (more rarely) a problem with reading your browser cache.
I'd review
https://github.com/JimmXinu/FanFicFa...erCacheFeature and try
setting use_browser_cache_only:true. It may also help to clear the browser cache--sometimes it's necessary to actually delete the cache dir contents manually. But I'd make a backup first.