~snip~
The main thing is there are assets (properties) that are still standing and being used to generate income. I know the exact buildings, locations, etc. They are listed on Booking.com and on the developer website too. I have copies of the deeds/titles of said properties.
~snip~
Then a number of properties were purchased in Thailand and I started receiving rent until COVID hit us.
I have no doubt that the properties are there, but the question is who are the owners who rent them out - it is possible that they are not the people behind the ICO in which you invested. It is possible that the real estate has been sold, and that seems the most logical - because if your business goes downhill, you can also face claims from clients, and then why risk something that can be seized and sold at auction.
What you need is a good lawyer who is familiar with real estate and also knows something about ICO/cryptocurrencies + to go with him to Thailand and try to find out on the spot who the owners of those properties are.