$uuid is not working with dexieCloud

[klinki]

Hello,

I have following database:

import Dexie, {Table} from "dexie";
import 'dexie-observable';
import dexieCloud from 'dexie-cloud-addon';
import {ulid} from "ulidx";

Dexie.Observable.createUUID = () => ulid();

export class DatabaseService extends Dexie {
  exercises!: Table<Exercise>;
  trainingPlans!: Table<TrainingPlan>;
  trainingPlanExercises!: Table<TrainingPlanExercise>;
  trainings!: Table<Training>;
  exerciseExecutions!: Table<ExerciseExecution>;
  profiles!: Table<Profile>;

  constructor() {
    super('MyDB', { addons: [dexieCloud] });

    this.version(2).stores({
      // Primary key and indexed props
      exercises: '$$id',
      trainingPlans: '$$id',
      trainings: '$$id',
      trainingPlanExercises: '[trainingPlanId+exerciseId]',
      exerciseExecutions: '$$id,exerciseId,date',
      profiles: 'id'
    });

  // ... more code follows ...
}

and locally it works perfectly.
Problem started when I tried to use dexieCloud.

Then adding new records to database fails with following error:

 DexieError2 {name: 'ConstraintError', message: 'Invalid primary key type Undefined for table exercises. Tables marked for sync has primary keys of type string or Array of string (and optional numbers)', inner: null}

(It fails pretty much for all tables, but in this case I tried to insert into exercises table).

I assume it has issue with $$ syntax. But how do I get around that? I really like using ulidx as primary key, they are very database friendly and also distributed systems friendly.