Sign Management Solution can not be redeployed and viewed in the My Solutions tab of ArcGIS Online Solutions once deleted from the Solutions Web App or Manually in My Contents, returning an error "failed to deploy".
This issue is non-reproducible. When deleting a Solution, delete the previously deployed Solution from the ArcGIS Solutions App: https://doc.arcgis.com/en/arcgis-solutions/latest/get-started/delete-an-arcgis-solution.htm. This ensures that all related content (e.g., groups, items, folders) is deleted in the process.
If this issue occurs, reach out to Esri Support Services as additional information is needed for further investigation.