Eloquent update json column with dot key

[AntistressStore]

I can't find any information on how to properly update json values with dots in the key. Can you tell me where to clarify this information and how to do it? Is it possible to do this by means Eloquent? ->update method Or only through a raw query?

in db column state, we have this data

{"2.7":35,"2.9":24,"2.95":8.99}

  protected $casts = [
        'state' => 'array',
    ];

I have all tried. With or without shielding. Values with dots are saved successfully. Keys with dots cannot be obtained and updated. don't work

Something::find(1005)->update(['state->2.95'=>8.7]);
Something::find(1005)->update(['state->2\.95'=>8.7]);
Something::find(1005)->update(['state[2.95]'=>8.99]);
Something::find(1005)->update(["state['2.95']"=>8.99]);
Something::find(1005)->update(['state->"2.95"'=>8.99]);

The operation is successful, but there is no result. The value does not change.

Having studied the operations that Eloquent. I've discovered several methods that split the key using a dot. There is also a method that checks whether this key is populated. Illuminate\Database\Eloquent\Concerns\GuardsAttributes::isFillable

/**
   * Determine if the given attribute may be mass assigned.
   *
   * @param  string  $key
   * @return bool
   */
  public function isFillable($key)
  {
      if (static::$unguarded) {
          return true;
      }

      // If the key is in the "fillable" array, we can of course assume that it's
      // a fillable attribute. Otherwise, we will check the guarded array when
      // we need to determine if the attribute is black-listed on the model.
      if (in_array($key, $this->getFillable())) {
          return true;
      }

      // If the attribute is explicitly listed in the "guarded" array then we can
      // return false immediately. This means this attribute is definitely not
      // fillable and there is no point in going any further in this method.
      if ($this->isGuarded($key)) {
          return false;
      }

      return empty($this->getFillable()) &&
          ! str_contains($key, '.') &&
          ! str_starts_with($key, '_');
  }

It is he who is responsible for the fact that a value with a key with a dot cannot be written down. It defines it as not writable.

If you experimentally comment out the last lines ! str_contains($key, '.'), the result will be recorded. But it is broken into separate keys. 2.7 becomes a nested array with keys 2 and 7.