The lymphocyte count can be borderline high than the normal levels due to previous infection in the recent past.
Its usually harmless as this can be temperorary after an illness.
As lymphocyte count is not associated with high total count or Wbc count it may not be related with any infection
But better to do tests like ESR,
thyroid function tests if you haven't done these tests.
Next Steps
i would suggest to do other blood tests like ESR,
Thyroid Function Tests(TFT) if u havent done these blood tests.
if there's any abnormal values in TFT, then do a serum anti TPO( Thyroid Peroxidase test) to rule out hashimotos thyroiditis.
if the results are normal, can repeat the same abnormal blood tests after 1 month.