We have also experienced this kind of message when we try to access our Web forms in Safari browsers. We asked Caspio Support for some assistance about this. As per them, "We have noticed that after the recent release of iOS 13, some users with Safari version 13.x have reported intermittent issues signing into Caspio applications. We are monitoring each iOS/Safari release so we can provide a solution that will fully support a stable release of Safari.
Caspio has added an overlaying message on Safari browser (only v.13+) that is used to access DataPages: “This version of Safari is not fully supported. Please use a different browser (e.g. Chrome, Firefox, Edge).” This message can be configured/removed in Localization of the DataPage."
One of there suggestion is if users are experiencing login issues after closing the message, following steps may help resolve this issue:
1. Go to Settings in your device.
2. Choose Safari.
3. Under Privacy & Security, click Clear History and Website Data.
4. Close all Safari windows and re-launch Safari.
And also, there's a way to remove the popup message that shows up on Caspio DataPages in Safari browsers.
Please follow these steps:
1. Edit Localization associated with your DataPage.
2. Scroll down to System Messages on the left.
3. Choose element 615 with the current message: This version of Safari is not fully supported. Please use a different browser (e.g. Chrome, Firefox, Edge).
4. Go to Custom Text area and remove the message: "This version of Safari is not fully supported. Please use a different browser (e.g. Chrome, Firefox, Edge)."
5. Save the Localization.
6. If you have redirections mentioned in Authentication, then edit Localizations of those DataPages as well.
I suggest to make a copy of the Localization attached to the DataPage and apply changes in the copied version. Assign the copied Localization to the DataPage.