Using DB::raw() statement in update converts the changed value to an array

[vetuk]

Q	A
Bug?	yes
New Feature?	no
Framework	Laravel
Framework version	7.15.0
Package version	10.0.0
PHP version	7.2.31

Actual Behaviour

I have the following code for creating / updating a record:

$this->updateOrCreate([
            'name' => $index->getIndex() . config('project.elastic.alias'),
        ], [
            'class' => get_class($index),
            'entity' => $index->getEntity(),
            'count' => DB::raw('count + 1'),
            'last_synced_at' => Carbon::now()
        ]);

Which inserts the following to my audits table:

old_values

"{""count"":7,""last_synced_at"":""2020-06-11 10:36:25""}",

new_values

"{""count"":{},""last_synced_at"":""2020-06-11T09:43:26.339184Z""}"

which of course gives the following error when I try to display audits for it:

htmlspecialchars() expects parameter 1 to be string, array given (View: /var/www/control-panel/resources/views/common/audits/results.blade.php)

My table definition for column count:

$table->unsignedInteger('count');

I have no special settings for this column in my model class.

Expected Behaviour

The new_values for the change in audits table should be like this:

"{""count"": 8,""last_synced_at"":""2020-06-11T09:43:26.339184Z""}"

Steps to Reproduce

I am not sure this is the problem for all DB::raw() or just for the specific one that I am using DB::raw('count + 1').

Thanks