Hi Bete Lube!
Sorry if I'm not able to help you properly, but I'm having a little difficulty understanding the scenario.
If my understanding is correct, when you are positioning the fields in the envelope before the first sending, you fill in some markings/texts but they do not appear to you. It’s only possible to view it after accessing the preview or making a correction. If this is the scenario, it really is unexpected behavior.
My recommendation is to go to Settings > Sending Settings > and enable the option "When an envelope is sent, write the initial value of the field for all recipients". Maybe this could help.
Also, I looked in our Release Notes to see if there were any changes to field visibility, but I couldn't find anything related to it. Therefore, my suggestion is that you check if another administrator has changed any settings in your account. To do this, go to Settings > Audit Logs.
If the problem still doesn't resolve, in this case, I recommend that you contact our customer support team and share some evidence (screenshots) of what is happening, so that the team can investigate a little deeper than me.