A user of ours experienced an issue that has a solution listed, here: https://community.esri.com/t5/arcgis-hub-questions/while-typing-text-cursor-keeps-jumping-to-the-top/m-p/604570/highlight/true#M3056
The user reports that when editing text on a Hub Site, after every keystroke the cursor jumps to the beginning of the text box. The issue does not occur when using the Edit in HTML option, so there is an easy workaround, however I'm not certain of the solution based on the resolved post, linked-above. Is there a solution on our end? If not, it seemed worth mentioning.