Laravel transaction not rolling back - php

Question

I'm trying to use Laravel transactions for an operation that requires a change in customer's balance.
In this specific situation, when an already approved (status = 1) process is edited, the update operation must subtract the current process amount and add the new process amount to the customer's wallet.
This is the current code:
$process = Process::findOrFail($id);
// CHECKS THE CURRENT PROCESS SUBSIDY
$old_subsidy = $process->subsidy;
try {
DB::beginTransaction();
$process->update($request->all());
// SUMS NEW PROCESS SUBSIDY ONLY WHEN PROCESS IS ALREADY APPROVED
if($process->status == 1) {
$customer = Customer::findOrFail($process->customer_id);
$customer->balance = $request->subsidy - $old_subsidy;
$customer->save();
}
DB::commit();
$notification = array(
'title' => __('Success'),
'message' => __('Process updated with success'),
'class' => 'bg-success'
);
return redirect()->route('processes.show',$process->id)->with($notification);
} catch (\Exception $e) {
DB::rollback();
$notification = array(
'title' => __('Erro'),
'message' => __('Ocorreu um erro'),
'class' => 'bg-danger'
);
return redirect()->back()->with($notification);
}
To test, i'm forcing an error, on this line, requesting a customer id that doesn't exist, like: $customer = Customer::findOrFail(99999). The error message is shown but the changes in the process are still being saved instead of roled back.
Am i missing something here?
Thanks in advance!