vuejs different v-ifs from a previous select - vue.js

Question

I am trying to display two different divs according to a select options, but I am only getting the first v-if. When I select "de", I do get the first div content, but I also get it when I select fr, instead of the second div.
I can't get my head around this. Any ideas of what I am getting wrong?
This goes on inside a form:
<select v-model="source" :key="source">
<option :value="de">de</option>
<option :value="fr">fr</option>
</select><br><br>
<div class="characters">
<div v-if="source === de" class="deChars" :key="source">
<h5>Special German characters:</h5>
<li v-for="character in deChars" :key="character">{{ character }}</li>
</div>
<div v-else-if="source === fr" class="frChars" :key="source">
<h5>Special French characters:</h5>
<li v-for="character in frChars" :key="character">{{ character }}</li>
</div>
<br>
</div>
on the script section I am using the options api with the data property source=" ", and two arrays for deChars and frChars.
note: those :key="source" I added to make sure it gets read when the source value changes.
The data properties:
data(){
return {
original: "",
translation: "",
source: "",
target: "en",
deChars: ["ä", "Ä", "é", "ö", "Ö", "ü", "Ü", "ß"],
frChars: ["à", "â", "ç", "é", "è", "ê", "ë", "î", "ï", "ô", "û", "ü", "œ"]
}
},
Thank you so much!

Answer 1

Try to remove the binding sign since it seems that de and fr are not declared as properties and they're just raw string :
<select v-model="source" >
<option value="de">de</option>
<option value="fr">fr</option>
</select>
then do v-if="source === 'de'" and v-else-if="source === 'fr'"

Answer 2

It seems that the problem was with the select options. THe binding seemed to mess about. Once I got rid of that, it works perfectly. So thanks for that Boussadjra. However, if on the v-if I change the de and fr to strings, it does not work. WHich is why I am adding this comment as the solution.