Fired Earth inside and outside paint=happy. Roof paint not!

I had bought Fired Earth Roof Paint for the 1st time upon the sale's person recommendation.

I was happy with their inside and outside wall paint over the past few years. Normally I only have to apply 2 coats to obtain good coverage. The paint was easy to mix and to apply. I found the product quite durable too and easy to clean.

I had painted the whole outside with "Infinite" about 4 years ago.

Then I painted the whole inside of a house with sisal and to date all is still looking great.

I could mix both these by myself with a plastic paint stirrer wand, no matter if the paint had not been used for weeks.

With my 1st 20liter of roof paint they shook it for me on the machine before leaving. A few weeks later when I wanted to paint I stirred as per usual in the past and app****. It was literally running off the walls. It seemed it had separated and just would not stick.

1)I loaded it up into the car. They exchanged the 20ltr and shook it. Once again I app**** it and all was good.

2)A few weeks later the same thing. Stir it myself. Runs of the walls. Back to builders to shake again and return home to apply.

3) during the Lockdown now again the same thing. Again back to builders sunningdale to shake so I can paint.

However This is just not good enough!

X3 return trips uploaded and offloading a 20ktr bucket of paint mostly on my own not to mention the schlep, inconvenience, effort and fuel.

I now want this product replaced with what I bought in the past, trusting that my paint shaking trips can come to a stop now.