Explanation
The most likely cause of this issue is that the printer had DHCP enabled, which changed its IP address after adding it to the print server and configuring it on each user's machine. DHCP (Dynamic Host Configuration Protocol) is a network protocol that assigns IP addresses and other network configuration parameters to devices automatically, without manual intervention. DHCP can simplify network management and avoid IP conflicts, but it can also cause problems if the devices are not configured to use static or reserved IP addresses.
If the printer had DHCP enabled, it might have received a different IP address from the DHCP server after rebooting or reconnecting to the network, which would make it unreachable by the print server and the users' machines that were configured with the previous IP address. Scanning to email would still work, as it does not depend on the print server or the users' machines, but on the printer's SMTP settings and internet connection. References: [CompTIA Server+ Certification Exam Objectives], Domain 4.0: Networking, Objective 4.l: Given a scenario, configure network settings for servers.