Hi @Anonymous ,
Could you please share a screenshot about your issue?
Do you mean that the "Paul" disappear when you type "pa" within your TextSearchBox?
Based on the issue that you mentioned, I have made a test on my side, and don't have the issue that you mentioned. The screenshot as below:
The StartsWith() function is used to test whether one text string begins with another. Please make sure the Client Name column is a Text type column in your Data source.
Also please consider take a try with the following formula in your Gallery:
Filter(DataSource, Textbox.Text in clientname)
Note: Above formula may cause a Delegation warning issue, if the amount of your data source records is not more than 2000, you could ignore this warning issue. Set the "Data row limit for Non-delegable queries" option to maximum value -- 2000 within Advanced settings of App settings of your app, then you could process 2000 records locally at most in your app.
Please also consider re-generate a new app based on your data source, then try your formula again, check if the issue is solved.
Best regards,