Good first dates but lackluster second dates?

Lately I've been getting more second dates due to breaking touch barrier and flirting more. While some of the first dates are good and we exchange numbers to set up a second date, I noticed that sometimes the second date tends to feel a bit more "empty" than the first one did.

There's more awkward silences and sometimes my mind just goes blank more. Even though I remain calm, I noticed that these silences usually don't result in more dates. Another thing is that sitting across from her also makes things harder than sitting next to her. It can put more pressure on both people if there is a silence and it's harder to break the touch barrier. Usually on dates when I'm sitting across, I'll still try to flirt and tease, but sometimes it just ends with us having a conversation and I never hear back again after that. It just lacks that spark and excitement the first one had

Do you have any tips on how I can be more consistent in getting past the second date and keeping their interest? Are awkward silences and having "just conversations" on dates usually a deal breaker? Or is there some element of luck involved in it too?