In case you WordPress admin and/or login pages got locked-in and the issue is not with plugins, double-check if if your domain is not using CloudFlare as proxy.

As of November 2016 CloudFlare changed its IPs. So, either exclude your admin/login pages from CloudFlare or add new CloudFlare IPs to your .htaccess

(IPv4)

allow from 199.27.128.0/21
allow from 173.245.48.0/20
allow from 103.21.244.0/22
allow from 103.22.200.0/22
allow from 103.31.4.0/22
allow from 141.101.64.0/18
allow from 108.162.192.0/18
allow from 190.93.240.0/20
allow from 188.114.96.0/20
allow from 197.234.240.0/22
allow from 198.41.128.0/17
allow from 162.158.0.0/15
allow from 104.16.0.0/12
allow from 172.64.0.0/13

(IPv6)
allow from 2400:cb00::/32
allow from 2405:8100::/32
allow from 2405:b500::/32
allow from 2606:4700::/32
allow from 2803:f800::/32
allow from 2c0f:f248::/32
allow from 2a06:98c0::/29

More in CloudFlare IPs: How do I whitelist CloudFlare's IPs in .htaccess?