Try re-enabling them now.
Sometimes what happens is those plugins have ‘cached’ the current styles.
And therefore you don’t see a new style you have applied. And clearing the plugin caches will fix the issue.
However, check in your PerfMatters and WP Rocket settings and try to make sure they are not performing duplicate options. For example: if PerfMatters is doing CSS optimizations, then DON’T enable that in WP Rocket ( or vice versa ).
Having 2 plugins doing the same thing will cause issues especially with style sheets.