App writes date values as tеxt in Google sheet

Hi, I am getting this bug which annoys me a lot and stops further development with Appsheet. I am getting dates written in google sheet by Appsheet app as text. All locales are set correctly and identically both on table properties in Appsheet and google sheet table. Columns are set to Dates on both sides too. But when i pick a date with appsheet date picker (Chrome) it adds strings to the value of the date when updating the Google sheet and the cell is automatically converted by Google sheet to text. This way I cannot make either any out-of-app calculations or load the table to Google Data studio for BI.
The locale is Bulgarian and it ads the string “г.” to the end, and the date becomes formatted like this “DD.MM.YYYY г.”. However, Appsheet treats this value as a Date and everything with dates within the app works fine.
Thanks for helping