I am experiencing this issue as well.
The workaround from this post allowed me to successfully login and re-add the Admin role. Thanks!
bash-5.1$ /opt/librenms/validate.php
===========================================
Component | Version
--------- | -------
LibreNMS | 23.8.2-20-g298d217a8 (2023-08-30T14:11:04-05:00)
DB Schema | 2023_06_18_201914_migrate_level_to_roles (257)
PHP | 8.1.14
Python | 3.9.16
Database | MariaDB 10.5.16-MariaDB
RRDTool | 1.7.2
SNMP | 5.9.1
===========================================
[OK] Composer Version: 2.5.8
[OK] Dependencies up-to-date.
[OK] Database connection successful
[OK] Database Schema is current
[OK] SQL Server meets minimum requirements
[OK] lower_case_table_names is enabled
[OK] MySQL engine is optimal
[OK] Database and column collations are correct
[OK] Database schema correct
[OK] MySQl and PHP time match
[OK] Active pollers found
[OK] Dispatcher Service not detected
[OK] Locks are functional
[OK] Python poller wrapper is polling
[OK] Redis is unavailable
[OK] rrd_dir is writable
[OK] rrdtool version ok
[root@LibreNMS ~]# cat /etc/os-release
NAME="Rocky Linux"
VERSION="9.2 (Blue Onyx)"
ID="rocky"
ID_LIKE="rhel centos fedora"
VERSION_ID="9.2"
PLATFORM_ID="platform:el9"
PRETTY_NAME="Rocky Linux 9.2 (Blue Onyx)"
ANSI_COLOR="0;32"
LOGO="fedora-logo-icon"
CPE_NAME="cpe:/o:rocky:rocky:9::baseos"
HOME_URL="https://rockylinux.org/"
BUG_REPORT_URL="https://bugs.rockylinux.org/"
SUPPORT_END="2032-05-31"
ROCKY_SUPPORT_PRODUCT="Rocky-Linux-9"
ROCKY_SUPPORT_PRODUCT_VERSION="9.2"
REDHAT_SUPPORT_PRODUCT="Rocky Linux"
REDHAT_SUPPORT_PRODUCT_VERSION="9.2"