Check the following.
Other devices on the network are turned on.
The network addresses (IP address, subnet mask, and default gateway) are correct if you are entering them manually.
The network addresses for other devices (subnet mask and default gateway) are the same.
The IP address does not conflict with other devices.
If your printer and network devices still do not connect after confirming the above, try the following.
Turn off the wireless router. Wait for about 10 seconds, and then turn it on.
Configure network settings again using the installer. You can run it from the following website.
https://epson.com/support (U.S.)
https://epson.ca/support (Canada)
https://latin.epson.com/support (Latin America)
https://epson.sn > Setup (Other regions)
You can register several passwords on a wireless router that uses WEP security type. If several passwords are registered, check if the first registered password is set on the printer.