TypeError: Cannot read properties of undefined on NestJS Dependency Injection

I'm getting TypeError: Cannot read properties of undefined (reading 'create') at AuthenticationService.register and have spent a lot of time reading this site (and others) trying to figure out what I'm missing. That Typeorm may be involved is where I know I'm outmatched—any help is appreciated.

users.module.ts

import { Module } from '@nestjs/common';
import { TypeOrmModule } from '@nestjs/typeorm';

import { User } from './user.entity';
import { UsersService } from './users.service';

@Module({
  imports: [TypeOrmModule.forFeature([User])],
  providers: [UsersService],
  exports: [UsersService],
})
export class UsersModule {}

users.service.ts

import { HttpException, HttpStatus, Injectable } from '@nestjs/common';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';

import { CreateUserDto } from './dto/create-user.dto';
import { User } from './user.entity';

@Injectable()
export class UsersService {
  constructor(
    @InjectRepository(User)
    private usersRepository: Repository<User>,
  ) {}

  async create(userData: CreateUserDto) {
    const newUser = await this.usersRepository.create(userData);
    await this.usersRepository.save(newUser);
    return newUser;
  }
}

authentication.module.ts

import { Module } from '@nestjs/common';
import { PassportModule } from '@nestjs/passport';

import { AuthenticationController } from './authentication.controller';
import { AuthenticationService } from './authentication.service';
import { UsersModule } from '../users/users.module';
import { LocalStrategy } from './local.strategy';
import { ConfigModule, ConfigService } from '@nestjs/config';
import { JwtModule } from '@nestjs/jwt';
import { JwtStrategy } from './jwt.strategy';

@Module({
  imports: [
    UsersModule,
    PassportModule,
    ConfigModule,
    JwtModule.registerAsync({
      imports: [ConfigModule],
      inject: [ConfigService],
      useFactory: async (configService: ConfigService) => ({
        secret: configService.get('JWT_SECRET'),
        signOptions: {
          expiresIn: `${configService.get('JWT_EXPIRATION_TIME')}`,
        },
      }),
    }),
  ],
  providers: [AuthenticationService, LocalStrategy, JwtStrategy],
  controllers: [AuthenticationController],
  exports: [AuthenticationService],
})
export class AuthenticationModule {}

authentication.service.ts

import { HttpException, HttpStatus } from '@nestjs/common';
import { ConfigService } from '@nestjs/config';
import { JwtService } from '@nestjs/jwt';
import * as bcrypt from 'bcrypt';
import { RegisterDto } from './dto/register.dto';
import { TokenPayload } from './token-payload.interface';
import { PostgresErrorCode } from '../database/postgres-error-codes.enum';
import { UsersService } from 'src/users/users.service';

export class AuthenticationService {
  constructor(
    private readonly configService: ConfigService,
    private readonly jwtService: JwtService,
    private readonly usersService: UsersService,
  ) {}

  public async register(registrationData: RegisterDto) {
    const hashedPassword = await bcrypt.hash(registrationData.password, 10);
    try {
      const createdUser = await this.usersService.create({
        ...registrationData,
        password: hashedPassword,
      });
      createdUser.password = undefined;
      return createdUser;
    } catch (error) {
      if (error?.code === PostgresErrorCode.UniqueViolation) {
        throw new HttpException(
          'User with that email already exists',
          HttpStatus.BAD_REQUEST,
        );
      }
      console.log(`error `, error);
      throw new HttpException(
        'Something went wrong',
        HttpStatus.INTERNAL_SERVER_ERROR,
      );
    }
  } 
}

authentication.controller.ts

import {
  Body,
  Req,
  Controller,
  HttpCode,
  Post,
  UseGuards,
  Res,
  Get,
} from '@nestjs/common';
import { AuthenticationService } from './authentication.service';
import { RegisterDto } from './dto/register.dto';
import { UsersService } from 'src/users/users.service';

@Controller('authentication')
export class AuthenticationController {
  constructor(
    private readonly authenticationService: AuthenticationService,
    private readonly usersService: UsersService,
  ) {}

 @Post('register')
  async register(@Body() registrationData: RegisterDto) {
    console.log(`registrationData: `, registrationData);
    // return this.usersService.create(registrationData); // This works
    return this.authenticationService.register(registrationData); // This throws error
  }
}