Netflix has a wonderful Thai movie out, Once Upon a Star. I haven't seen The Undertaker. People don't realize just how small the Thai industry is. Even if you only work around the edges, you'll soon know everybody involved. It's small because Thai language films struggle to support themselves with a domestic box office or TV/online distribution. Thai films, with an exception every now and then, just don't export well. Fact is, the industry has been dependent on (primarily) American productions seeking cheap offshore locations that cut corners (see people wearing flip flops on set, instead of steel toed boots, lights rushed up without sandbags in order to squeeze in extra setups). I suppose the companies still dominating things are Living Films, Grand Elephant, and Kantana. There' s an American owned production company, Greenlight, that's also fairly active. The rest is mainly boutique production houses, with many for animation piece work. Thai film directors still need to work other jobs to earn a living. It all lacks a certain amount of focus.
Here's what Thai filmmakers do well: cinematography, set design, art direction. They make good horror films. Less well are acting and especially sound. Frankly, I'd rather watch old Thai cinema from the 50s, 60s, and 70s than most of the stuff put out today.