Moved Jobs Tax Office asking for 30% Rule Addendum

Hi Everyone,

Wondering if I can get some insight from other people into this issue I'm having specifically with the 30% rule.
I came to NL in April 2018 and was granted the 30% rule. I worked at this company until November 2020 and then moved to a new company and started the process to re-apply for the 30% rule.

When applying for the 30% rule again the tax office noticed that my taxable income did not meet the minimum threshold for the year 2018. There has been a correction calculated to raise my minimum taxable income above the threshold for the year 2018.
The second thing is that the tax office has asked for an 'addendum' that declares how the reduction is calculated. I nor my previous employer have a copy of this neither in my work contract nor as a separate document, I cant remember if it was signed or not.

I guess the question is, is this solvable? And if not what will be the consequences of this?

Any insight would be fantastic!
Thanks,
Alex.