Lately, there have been many cases of Facebook accounts being randomly suspended for being compromised or blocked for unusual activities. Most of the time Facebook does this to protect your account and will unlock it after some hours or if you provide the required information.
It is really difficult to pinpoint the exact problem of what is happening with your account. If your account keeps being suspended after being reinstated, then there is a likelihood that your network IP address has been blacklisted.
For now, clear your browser cookies, remove any suspicious browser add-ons, and scan your devices for any malicious software. Also, change your network IP address.
Learn more about keeping your Facebook account secure or visit Facebook Help Center for support.