hidden terminal prompt

I am experiencing a problem (Solar-PuTTY 3.0.1.119) on Windows 10 64-bit.

Display resolution 1920 x 1080.

After starting a session and outputting a text file with many strings. The terminal prompt hides behind the content. The windows size should be changed by the mouse, to make the prompt available. Then the scrolls element appears and the prompt becomes available till the end of the session. I feel really uncomfortable with that. Any solution?