Having trouble connecting Laravel 6.2 (phpredis, php7.3) to DigitalOcean Managed Redis instance

I’m looking to scale my application from a single server to multiple, so I’ve set up a brand new Redis managed database. After trying to point my Laravel app to use it I’m getting a read error on connection error. Having scouted around the internet for the best part of a day, I’ve realised that it doesn’t seem to be a common issue. I’m running Laravel 6.2, phpredis 5.1.1 and php 7.3.13. I’ve allowed my droplet to access the Redis instance over private networking.

My config/database looks like this:

'redis' => [

			'client'  => 'phpredis',
			'cluster' => false,

			'default' => [
				'scheme'   => 'tls',
				'host'     => env('REDIS_HOST', '127.0.0.1'),
				'password' => env('REDIS_PASSWORD', null),
				'port'     => env('REDIS_PORT', 6379),
				'database' => env('REDIS_DB', 0),
			],

			'cache'   => [
				'scheme'   => 'tls',
				'host'     => env('REDIS_HOST', '127.0.0.1'),
				'password' => env('REDIS_PASSWORD', null),
				'port'     => env('REDIS_PORT', 6379),
				'database' => env('REDIS_CACHE_DB', 1),
			],
			'options' => [
				'prefix'     => env('REDIS_PREFIX', Str::slug(env('APP_ENV', 'ENVNOTDEFINED'), '_').'_database_'),
				'parameters' => ['password' => env('REDIS_PASSWORD', null)],
			],
		]

And my .env file contains the required values:

REDIS_HOST=DATABASE_URL.db.ondigitalocean.com
REDIS_PASSWORD=PASSWORD
REDIS_PORT=25061

I found this question, but because I’m already running later versions than the suggested fix, the answer didn’t solve my problem.

Has anyone encountered this before?