5A resale flat with a budget (without ID)

[5A resale flat with a budget (without ID)]

Good afternoon. The end result of your renovation work is very lovely. If you do not mind, I'd like your contractor's details to pass on to my aunt who's planning to start her renovation works within the next couple of months. My email is joelngjiaen@gmail.com. Have a good day!

[Vinyl flooring overlay issues]

Hi, I'm new to the renovation scenario. I've recently completed my renovations, and found out that the flooring has even lines spreading across the floor. You can walk across it and it feels levelled just fine, but visually it looks like there are dips on the surface. When I asked my contractor about it, he tells me that it's because of the tiles below which causes this overlay issue.

I've attached an image.

Anybody ever experienced this issue before? Any advice you could share?