Bitlocker corruption in dual-boot

Steps i took to end up with this corruption:

• Installed Windows 10 Pro 20H2 (from now on Windows#1) in a freshly cleaned GPT drive. Did all updates, programs setup and it was all good.
• Activated Bitlocker on Windows#1 volume (XTS-AES, full encryption, did the pre-encryption reboot test). All good, test successful and then got the drive fully encrypted.
• Shrank the Windows#1 Bitlocker volume by 256 GB (down from 1TB).
• Installed Windows 10 Pro 1809V2 (Windows#2) in this newly unallocated space. Successful and working. At this point Windows#2 is also the default boot option.

Then i activated Bitlocker on Windows#2 volume. As before i choose XTS-AES, full encryption and to do the pre-encryption reboot test, except this time i was greeted at reboot with the Bitlocker recovery page which asked for the numerical recovery password, only for it to instantly reboot when i tried to enter it (correctly 100%).
At this point i was sure something bad happened and feared for the Windows#1, but after a reboot i was able to log into that installation without issue.
Inside Windows#1 i did some troubleshooting, and here is the output (C: being Windows#1 and H: being Windows#2):

manage-bde -status

Volume C: [system]
[OS Volume]

    Size:                 697,27 GB
    BitLocker Version:    2.0
    Conversion Status:    Fully Encrypted
    Percentage Encrypted: 100,0%
    Encryption Method:    XTS-AES 128
    Protection Status:    Protection On
    Lock Status:          Unlocked
    Identification Field: Unknown
    Key Protectors:
        TPM
        Numerical Password

Volume H: [Label Unknown]
[Data Volume]

    Size:                 Unknown GB
    BitLocker Version:    2.0
    Conversion Status:    Unknown
    Percentage Encrypted: Unknown%
    Encryption Method:    XTS-AES 128
    Protection Status:    Unknown
    Lock Status:          Locked
    Identification Field: Unknown
    Automatic Unlock:     Disabled
    Key Protectors:
        TPM
        Numerical Password

repair-bde H: C:\image.img -rp XXXXXX-XXXXXX-XXXXXX-XXXXXX-XXXXXX-XXXXXX-XXXXXX-XXXXXX -Force

BitLocker Drive Encryption: Repair Tool version 10.0.19041
Copyright (C) 2013 Microsoft Corporation. All rights reserved.

Beginning scan for BitLocker metadata.

Scanning boot sectors for pointer to metadata: 100%
Scanning sector boundaries for metadata:   1%
LOG ERROR: 0xc0000033
Failed to authenticate using supplied recovery information. (0x80070057)
LOG ERROR: 0xc000003b
Could not validate metadata at offset 67616768. (0x80070057)
LOG ERROR: 0xc0000033
Failed to authenticate using supplied recovery information. (0x80070057)
LOG ERROR: 0xc000003b
Could not validate metadata at offset 1140850688. (0x80070057)
LOG ERROR: 0xc0000033
Failed to authenticate using supplied recovery information. (0x80070057)
LOG ERROR: 0xc000003b
Could not validate metadata at offset 2214592512. (0x80070057)
Scanning sector boundaries for metadata:   2%
LOG WARNING: 0x8000003a
Proper metadata signature found, but the metadata is invalid. (0x80310010)
LOG ERROR: 0xc000003b
Could not validate metadata at offset 7303756288. (0x80310010)
Scanning sector boundaries for metadata: 100%
Finished scanning for BitLocker metadata.

ERROR: Cannot use 'XXXXXX-XXXXXX-XXXXXX-XXXXXX-XXXXXX-XXXXXX-XXXXXX-XXXXXX' to
unlock the input volume. Please try a different recovery password, recovery key
or password.

The numerical recovery password used in both the boot page and with repair-bde is absolutely correct, no chance of confusion here.

One additional thing i tried is switch the default Windows boot, but it didn't change anything.

I am completely at a loss here. I know Bitlocker is a bit quirky but i always expected the recovery keys to work (and they did up until now every time i needed to use them, even on catastrophic failures).

PS: just want to add that no data is being lost here, only hours of installing and setting up the OS and applications.