On the ESXi host(s), the file /var/log/lifecycle.log shows that the host is having issues connecting to the VMware Update Manager (VUM) server:
<TIMESTAMP> Wa(12) lifecycle[2105538]: Downloader:214 Download failed: ('<VUM_URL>:9084/vum/repository/hostupdate/vmw/vib20/trx/VMware_bootbank_trx_8.0.3-0.79.24859861.vib', '/tmp/vibdownload/VMware_bootbank_trx_8.0.3-0.79.24859861.vib', 'Incomplete download from<VUM_URL>:9084/vum/repository/hostupdate/vmw/vib20/trx/VMware_bootbank_trx_8.0.3-0.79.24859861.vib, received 7865298 bytes, expecting 7884838 bytes'), 9 retry left...
Note that the VIB name may be different.
vSphere 8.0
Slow / intermittent access to the VUM server
Investigate and resolve networking issues between the ESXi host(s) and the VUM Server.