With the old version of ClipFix, it was usually necessary to reduce the level of the audio before applying ClipFix so that there is room for the restored peaks. The current version of ClipFix has an extra control so that this can be done at the same time. See: https://manual.audacityteam.org/man/clip_fix.html
Note that Audacity 2.2.1 is a very old version of Audacity. The current version is 2.3.3 and is available via the Audacity website: https://www.audacityteam.org/download/windows/