What has happened here? DIY screenprinting problem and solutions.

I had the chance to print a design for a local rock band.
Some of the shirts after the first washing machine cycle were ruined (the print seems crumbled).

So what has happened?

First, I washed the t-shirt to take the finissage glues off, after the drying, I have used the iron to fix the color as usual.

So what could be the problem?

Too early wash or high-temperature cycle? It seems not.

Finally, I understand that, by using a bicomponent color, I added too much fixer and this caused an unstable print.

I fix the error by reprinting over.