A firewalld bugfix update has been released for CentOS 7.

CEBA-2021:1398 CentOS 7 firewalld BugFix Update

CentOS Errata and Bugfix Advisory 2021:1398

Upstream details at :   https://access.redhat.com/errata/RHBA-2021:1398

The following updated files have been uploaded and are currently
syncing to the mirrors: ( sha256sum Filename )

x86_64:
2ba8ed563d8e7d31e393c915f3705b7c8c4c991ca337616916c90e4a14049411 firewall-applet-0.6.3-13.el7_9.noarch.rpm
a2b22dc88f61d0fa6de4fcb62e090f383e630fc264c56ad005c9c508b1c0fcb2 firewall-config-0.6.3-13.el7_9.noarch.rpm
36e338a02697b1f86cb751a4d30e96bbb9a01a424dfe6f050474e28f832d3b2d firewalld-0.6.3-13.el7_9.noarch.rpm
4706b7d5da4cf50b5e9a1e2b512bf1746aac5d7ff7525f047e6a79a392d7f548 firewalld-filesystem-0.6.3-13.el7_9.noarch.rpm
3d130588e8e704895aa41cc1d3a57139effbcdabe57ea04b561e8d3b1d252e41 python-firewall-0.6.3-13.el7_9.noarch.rpm

Source:
974f72fe7e519e87b49efb0c4c56efb947bbff4e2b1309005f50b541046a197c firewalld-0.6.3-13.el7_9.src.rpm