TS search not identifying new bond formation

Hi, I have a question regarding the TS search module in Dmol3. I have created a products and reactants file and matched the atoms correctly. However, upon calculation, I receive many imaginary frequencies but none of which represent the new bond formation. My reaction involves nucleophilic aromatic substitution and thus a new bond is formed between an anion/nucleophile and an aromatic carbon unit. I have tried running the TS search both with an ungeometric optimised reactant as well as optimised, both yielded different imaginary frequencies but neither with the expected bond formation mode. Does anyone have any tips?