Say, there is an increase in demand for dollars (as compared to the other currency, say yen), which will put appreciation pressures on dollar.
Then to counter this appreciation, we need to buy yen. This will increase supply of dollars - hence moderate the appreciation pressures.
Now, because of inflationary pressure, open market operations (OMOs) will be carried out to sell bonds and buy dollars.
But would it not decrease the dollar supply and again appreciate the currency?