This is technically for the base plugin but since we discovered the issue internally I am posting here.

On inmotion shared servers the option for system zip disappeared around mid June. Many customers and imh agents reported the issues with backups timing out and we discovered that most of them were previously using system_zip but are falling back to pcl_zip since system_zip is unavailable.

As of last week the system zip option disappeared from the plugin on my vps.
while troubleshooting I ran which zip from the command line and it fixed it temporarily on that site only. After selecting system zip under the backup process settings and hitting save the preflight check showed that system zip was no longer available again and the options reverted to pclzip. Added a capture of this behavior below

Updating line 283 of class-boldgrid-backup-admin-compressor-system-zip-test.php to both of the following worked enabling system zip, the first one intermittently and the second one has been working consistently

if ( ! $this->core->execute_command( 'which zip; /bin/zip -v ' ) ) {

if ( ! $this->core->execute_command( 'zip -v ' ) ) {

Elana and brandon tried the same fixes I did on their own servers with no luck, system zip still showed as unavailable. My site was running php 7.4 and theirs were both on 8.3. After switching to php 7.4 brandon was able to successfully use system zip with both fixes above.

On shared servers the fixes above did not seem to fix the issue, but after checking one of the sites we were testing this on previously it looks like we were able to get it to work on shared and I was able to successfully run backups with system zip. Brad had worked on this one and made changes to the code but I haven't been able to figure out what fixed it and copying the zip of the plugin he made changes to to my vps it doesn't seem to fix it on my end. Brandon was able to combine my fixes with the modified version of the plugin on php 7.4 and it worked on his server. I attached the zip of the modified version below: