Not every silent consonant wakes up before a vowel. A quick map of when liaison is required, when it's a choice, and when it's banned.
Liaison isn’t all-or-nothing. There are three cases, and knowing which is which saves a lot of second-guessing.
Obligatory
After short function words: les‿amis, mon‿ami, nous‿avons. These are
locked in — skipping them sounds wrong.
Optional
After many verbs and longer adverbs, liaison is a register choice. Formal speech tends to make more of them; casual speech drops them.
Forbidden
After et, before an h-aspiré (les | héros), and after singular nouns.
Here the consonant stays silent no matter what follows.