Yes, you need to file Form 1120-S. As @Anonymous_ stated: "As long as your S corporation election is effective you are required to file an 1120-S."
From 2020 Instructions for Form 1120-S:
A corporation or other entity must file Form 1120-S if (a) it elected to be an S corporation by filing Form 2553, (b) the IRS accepted the election, and (c) the election remains in effect.
