Hello,
Could you please edit your question and attach a troubleshoot file? Just ensure that the router has been running for some time, and when the issue occurs, download the troubleshoot file before making any changes or rebooting the device. To download the troubleshoot file, navigate to System -> Administration -> Troubleshoot. This file can provide further insights into the issues you're experiencing. The attached files are only visible to Teltonika moderators.
Regarding your third point about connecting the RUT955 in client mode to Hotspots with a captive portal:
Currently, there are known issues with this. However, the support for this feature is planned in the upcoming v7.5 firmware. The release of v7.5 firmware is expected around mid-summer. There is also a possibility that this feature may even be released earlier with v7.4.4 if all goes smoothly. You can find more information about this topic in a forum thread here.
Kind Regards,
Andzej