Dmx.app.set giving undefined value

I have a variable created with id ‘test1a’ with value of ‘xyz’. In a javascript function, I am trying to set the value of this variable using dmx.app.set(‘test1a’, test1b) to use in the text on my page and in a progress bar through app connect. However the text originally shows ‘xyz’ as expected after running the function the text disappears, and the logs show undefined. Does anyone know the mistake I am making? Thanks

Variable definition:
<dmx-value id="test1a" dmx-bind:value="'xyz'"></dmx-value>

Javascript code:
var test1b = ‘abc’;
console.log(‘set_test1b’);
console.log(test1b);
dmx.app.set(‘test1a’, test1b)
console.log(‘set_test1a’);
var testres1 = dmx.parse(‘test1a.value’);
console.log(testres1);

Logs:
settest1b
abc
settest1a
undefined