Does anyone know how you can check where a website is being blocked.

A very vanilla Dutch classified site
Marktplaats - De plek om Nieuwe en Tweedehands spullen te kopen en verkopen
Or an equally vanilla Bulgaria forum
Bulgarian property directory & information on properties in bulgaria for sale or rent

Both get no response from my True account with no proxy

Work fine with a UK based proxy.

Is it that the site owners thinks anyone in Thailand is a scumbag who should be banned automatically (I have some sympathy ... hehe)?
Or is it gov.th not wanting you to check who's selling dirty knickers in Amsterdam? Now guys not what I was looking at at all. No idea what they would want to ban from Bulgaria though?