Laravel/Vue - PUT Method with Axios - Cannot update image file

I'm trying to update an icon with axios and put method on a laravel/vue app.

I'm always getting the error : icon must be an image.

I've correctly inserted my headers : content-type": "multipart/form-data" in the config variable.

  async updateSolution({
    commit
  }, payload) {
    const id = payload.id;
    const config = payload.config;
    const solution = payload.data;
    try {
      console.log(solution.get('icon'));
      const res = await this.$axios.$put(`/api/solutions/${id}`, {
        config,
        name: solution.get('name'),
        description: solution.get('description'),
        icon: solution.get('icon'),
      });
      commit('UPDATE_SOLUTION', res);
    } catch (error) {}
  },

If I do a console.log(solution.get('icon') here is the output :

File {name: 'img.png', lastModified: 1660039998282, lastModifiedDate: Tue Aug 09 2022 12:13:18 GMT+0200 (Central European Summer Time), webkitRelativePath: '', size: 9026, …}
lastModified: 1660039998282
lastModifiedDate: Tue Aug 09 2022 12:13:18 GMT+0200 (Central European Summer Time) {}
name: "img.png"
size: 9026
type: "image/png"
webkitRelativePath: ""
[[Prototype]]: File

So it understand well that there is a image file in actions.js vuex file.

Why does it tell me that this is not an image ?

I heard about the workaround with _method parameter, so I've first tried adding the method in formData object :

async editSolution() {
      const result = await this.$refs.observer.validate();
      this.message = null;
      this.errors = [];
      let formData = new FormData();
      const id = this.id;
      const config = {
        headers: {
          "content-type": "multipart/form-data",
        },
      };
      formData.append("name", this.solutionName);
      formData.append("description", this.solutionDesc);
      formData.append("icon", this.solutionIcon);
      formData.append("_method", "PUT");
      this.$emit("edit-data", id, formData, config);
    },

Here the output is : The POST method is not supported for this route. So the parameter is not recognized apparently.

I also tried to add the parameter in the actions.js vuex file directly.

const res = await this.$axios.$post(`/api/solutions/${id}`, {
        _method: 'PUT',
        config,
        name: solution.get('name'),
        description: solution.get('description'),
        icon: solution.get('icon'),
      })

It gives me the same error than using this.$axios.$put() call : icon must be an image.

Thanks for your help,