VeraCrypt had the same problem. If Windows had installed an upgrade, the VeraCrypt UEFI bootloader was broken. With VeraCrypt version 1.24 the problem was solved. I tested it myself: it worked reliably for me!
released this on 7 Oct 2019
Fix issue related to Windows Update breaking VeraCrypt UEFI bootloader.
Is it one of these changes?
(1) Windows: Fix issue in UI for configuration autofix mechanism of bootloader
(2) Windows: Use correct parameters for 2nd call to SetStartExec in BootEncryption::InstallBootLoader
(3) Windows: Add UI options to control the behavior of automatic bootloader fixing when System Encryption used.
(4) Windows MBR Bootloader: workaround for SSD disks that don't allow write operations in BIOS mode with buffers less than 4096 bytes
(5) Windows: Restore veraCrypt boot meny entry for system encryption more often, especially during PostOOBE calls, and handle additional cor...
(6) Windows: only update MBR first 512 bytes if they have changed and don't update full MBR bootload in case of PostOOBE
(7) Windows: for system encryption case, also perform automatic fix of boot configuration if MBR boot used and not only EFI.