E-s visa applicants from Ukraine and other post-Soviet states frequently have difficulties with proving the source of income, because almost no one trusts banks or most individuals do not use bank accounts in Ukraine, Azerbaijan and other post-Soviet countries. Most transactions in those countries are made in cash due to the undeveloped and fragile banking system. Even if it is a sale of real estate, the initial transfer of funds occurs through a bank account, but then the seller immediately withdraws the funds and stores it in the form of cash. Income and taxes are very poorly documented. The good news is that the consulate there is aware of those conditions and is more liberal about tracking cash transaction. However, the USCIS here is not well aware of it and often denies change of status cases due to a lack of evidence proving source of funds invested. Therefore, I never recommend my clients from post-Soviet countries to file for change of status, and instead, advise them to go through the US consulate in their home country.
Additionally, the process through the consulate is more collaborative. If the consular officer is not satisfied with the evidence provided or has additional questions, you can go back and forth until the officer is satisfied. However, if you apply for change of status in the US, you do not get to communicate with the USCIS officer, other than responding to one dry request for evidence. If the USCIS officer makes an adverse decision, you are out of luck and run the risk of being deportable. Therefore, we always recommend to apply for E visa through the US consulate in the applicant’s home country.
Finally, applying for change of status inside the US is always a negative factor for your future visa applications through the consulate. The consulates are not happy when one enters the US with one type of visa and then changes it to another. Even if your change of status in the US is granted, you will still have to obtain the visa through the consulate whenever you decide to travel abroad. So, we recommend to apply from the consulate from the beginning and avoid dealing with the USCIS altogether.