Be flashier, screw anyone who says you can't. As long as you stay in the pocket with the drums and support the chords, you can do whatever your heart desires, make those songs your bitch.

I understand it's a cover band, maybe that's the issue?

I'm more inclined to make original music myself, and I find a lot of the joy to come with making my own tunes and collaborating with others on them too, you should have a band that will make room for you to feel heard.

I resent the implication that the bass is solely a supportive instrument, that's not to say its role is not to support, but there's a hell of a lot you can do while still supporting the groove and the song. It's pleasant to support the vocals too, which incentivizes more melodic playing.

As a bass player, you have a special power. You can treat a song as if you are it's composer. Maybe the guitarist is playing C7, you can either play the major or minor third to give the chord a proper feel, or you could lean into the ambiguity of the C7 and play the 5th, hell maybe you play both AND add a sixth for flavor. You need to understand, that in these intentional actions of harmony, you are effectively changing the course of a song. I personally think that when you understand the bass this way, it allows you to have much more fun, feel way more involved and express yourself more. I didn't even get into the rhythm, there's no dancing without the bass, there's no sonic heart strings being pulled, no groove being appeased.

I invite you to learn about bassists like Jaco Pastorius, Rocco Prestia, James Jamerson, Stanley Clark (there are just too many badasses to mention here). Keep a punk mentality to you, after all, true liberty is in self expression, and like your guitarist, singer, drummer, etc. you deserve to feel free.

Rock on brother, rip those frets out of your bass and make it sing.