Flickering LED Tape

I am trying to make a ceiling light and have cobbled together a test item (I know it looks like it was made by a blind man!) - it’s just proof of concept for now. I am having trouble getting the LED to dim successfully without flickering. I have a Varilight 1 Gang 120w 2 Way V-PRO Silent Trailing Edge LED Dimmer switch connected to a Varilight 240v AC To 12v DC Dimmable Power Supply - 40w for LED Tape. I am hoping that these 2 items will be in the finished item.

The current LED strips are just some old ones which were salvaged from a commercial shop sign. They work fine with their original LED Power Supply but flicker when dimmed.

Before I purchase the new LED strips, can anyone comment on the current set up please.
Are the 3 items currently compatible with each other - should they be flicker free?
I want warm white LED (approx 5m), are there any particular ones which I should go for?

Many thanks.

My guess is that the "reclaimed" LEDs are not dimmer-able.
The photo shows a simple LED with a voltage dropper resisitor. You wont be able to dim those!

I used this and it has worked fine. The strip is clearly designed to dim, but the TCP has only one white temperature, left, plus colour centre, but the Lidi version had varying white temperatures, was far more rugged, and only 3 meters long, and have to wait for them to be on offer. So the Lidi does centre floor to ceiling Billy book case, and two TCP units do midway to ceiling two units each, at 1% to 100% that is far more control to what one can expect with a dimmer switch. So can use the lights to supplement the room lighting or for decoration depending on brightness set.

I know the TCP can be connected to phone microphone, and react to noises in the room, but never really used it. But better to buy as a complete kit so you know they will all work together