The 1982 decision did not prevent small adjustments against the D-mark in 1983, 1986 and 1987. These adjustments took place in connection with adjustments demanded by other countries. France also stopped adjusting the parity after 1987.
That is noticeably slower than the outcomes for 1998 and 1999 (which were exceptional). But it is still a better performance than those in the US and most other major countries, and better than an extrapolation of historical experience in previous global downturns might have suggested.