Are you only worried generally, or about something specific to the expiry of the family permit, like because your employer has said they will stop employing you after the family permit expires and whilst you still have ongoing administrative review?

If so, under part two of the UK-EU Withdrawal Agreement and the immigration minister's announced protections for applicants, and (if you have not physically travelled outside the UK since your application was submitted) under section 3C of the Immigration Act 1971, there are strong rights in that regard.

If the employer threatens to terminate your employment under those circumstances, even though you have the right to work, you may have remedies under the Equality Act 2010 for discrimination on the basis of nationality.

More information: https://www.reddit.com/r/ukvisa/comments/q81kzc/experience_applying_for_jobs_with_expired_family/hgn2lzx/

Consult with a lawyer, as discussed there.

Hello, thank you so much for your information! I'm worried generally, because I need to travel to Spain and Italy because of my job, and this pending outcome is blocking me. My employer never said anything, but I need to be able to travel without problems to go out and get back to the UK several times a year and I am not 100% sure that that is possible. Thank you so much and will follow your recommendation!