You might be able to do it for force reinstalling the repo pkg from:
https://pkg00-atx.netgate.com/pfSense_v2_4_3_amd64-pfSense_v2_4_3/All/pfSense-repo-2.4.3_4.txz
Then selecting previous version. However even that looks like it's set to use 2.4.4.
So maybe:
https://pkg00-atx.netgate.com/pfSense_v2_4_2_amd64-pfSense_v2_4_2/All/pfSense-repo-2.4.2_3.txz
Or create a custom repo conf file:
FreeBSD: { enabled: no } pfSense-core: { url: "pkg+https://pkg.pfsense.org/pfSense_v2_4_3_amd64-core", mirror_type: "srv", signature_type: "fingerprints", fingerprints: "/usr/local/share/pfSense/keys/pkg", enabled: yes } pfSense: { url: "pkg+https://pkg.pfsense.org/pfSense_v2_4_3_amd64-pfSense_v2_4_3", mirror_type: "srv", signature_type: "fingerprints", fingerprints: "/usr/local/share/pfSense/keys/pkg", enabled: yes }