Integer not considered as integer

Dear all,

In the frame of our migration to CHT, I have a rather long and complex XLS Form that is previously used in ODK without issues.

In CHT a couple of things seem to be different. One major difference that I would like to discuss here is how a “integer” type entry in the XLS form is considered in CHT.

I have a calculate field that basically sums up two previously entered integers:
calculate: ${integer1}*7 + ${integer2}

In CHT I get a string concatenate.
For instance if integer1 = 10 and integer2=5
I will get as a result in CHT: 705
In ODK Collect I get: 75 what I was expecting.

Only when I write the calculate as:
${integer1}*10 + number(${integer2}) it works.

But this is a cumbersome syntax. Is there something I should do better?
How tell CHT to consider integer fields as numbers per default?