Custom brush keeps resetting

Im new to illustrator and hoping someone can help.

I am currently attempting to draw on the ipad version and have created a custom 'calligraphic brush' where the start and end are pointy but the middle has a roundness.

It constantly keeps resetting the brush to a larger size with no pointy ends. Not only does the brush reset, but it resets everything that i already drew with the 'custom' brush and throws everything off. 

It is extremely frustrating as this keeps happening over and over and over again and i dont understand why? When I go into the brush i created under "document", the 'custom' brush no longer looks like how i saved it (and drew with), but its just a basic round brush.

The workaround I found is to keep creating a new custom brush with the same settings (I have created 6 copies of it so far) and every single one resets after some time.

Is this an ipad glitch? or am I missing something?