At Compile time DefaultValueAttribute will likely not impression the generated IL and it won't be go through to initialize the property to that value (see DefaultValue attribute is not really working with my Car Property). So your DataContext for "video_length_textbox" is set to alone, as well as your IncrementingTextBox course https://aipljoydistrictgurgaon.sport.blog/2025/07/10/jms-floors-manesar-nature-inspired-low-rise-homes-in-gurgaon/