If the situation is as you have mentioned, the divorce did not take place, because
it was based on a suspicion before the occurrence of divorce itself, and it became evident later that it is not true. Returning to her is based on the divorce that has taken place, which is not true. Thus, you do not need to do anything to return to her; (Part No. 20; Page No. 191) she is still your wife by virtue of the current marriage contract. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.