Hi @hilagut @fabien @Schoonology , Loopack team,
The code is converting Json object string. We debugged and found the issue with Cassandra.prototype.create function in loopback-connector-cassandra/lib/cassandra.js. Please provide the solution for the issue.

model class
import {Entity, model, property} from '@loopback/repository';
@model()
export class Address {
@Property({
type: 'string'
})
street: string;

@Property({
type: 'string'
})
city: string;

@Property({
type: 'string'
})
state_or_province: string;

@Property({
type: 'string'
})
postal_code: string;

@Property({
type: 'string'
})
country: string;
}
@model({name: 'hotels'})
export class Hotels extends Entity {
@Property({
type: 'string',
id: true,
})
id?: string;

@Property({
type: 'string',
required: true,
})
name: string;

@Property({
type: 'string',
required: true,
})
phone: string;

@Property({
type: 'Object',
required: true
})
address: Address;

@Property({
type: 'array',
itemType: 'string'
})
pois: string[];

// Define well-known properties here

// Indexer property to allow additional data
// eslint-disable-next-line @typescript-eslint/no-explicit-any
[prop: string]: any;

constructor(data?: Partial) {
super(data);
}
}

export interface HotelsRelations {
// describe navigational properties here
}

export type HotelsWithRelations = Hotels & HotelsRelations;