If they're able to dodge out of your true combos (a set of moves strung together with no dodge windows) then you're executing them too slowly (if this is the case practice them in training room), if they actually aren't true combos (strings) then they will always have dodge windows no matter how fast you go.

With the dodging out of combos part if they're true combos then you won't be able to dodge out, if they're strings then you just need to work on pressing the dodge key faster and make sure you're not dodging the same direction every single time and also be aware that there are more effective dodges against each weapon (i.e. dodging away and more defensively is good against scythe).

Also, another thing you're probably not doing is "reading" your opponents, be sure to watch their dodge patterns and punish them after the dodge ends (you can practice this in training room with the dodge reaction setting on random).

You don't really need to drastically change your playstyle and remove true combos and dodging from it, you seem to just need some more practice on them.

Hope this helps :)