OK let's get this fixed:)
1. Where is this htaccess file located? In the same directory as your community? If it's in the same directory, THEN you're not using the IPS rewrite rules, hence you should make sure that the ACP => System => Search Engine Optimization - Rewrite URLs? Setting is disabled.
If you want to have the rewrite rules enabled, you have to make sure that their htaccess content + yours from IPS is present!
I assume all this happened once they(or you ) disabled the WAF settings ( that's literally what these 2 lines are doing) to fix your initial issue:D
So they, or you have probably replaced the existing htaccess IPS file.