Troubleshooting: Line Items Will Not Save
Recently Jetpack has caused a compatibility issue where line items and other information will not save for estimates and invoices. The exact issue is still being working out, since not everyone with the latest version of Jetpack is experiencing this issue. If you have this issue please troubleshoot by disabling some features (not just Jetpack). The issue may revolve around the PHP version you have, so please let support know the PHP version your server uses too.
Hopefully we will have this resolved shortly.