To reproduce:
1. Set registry entry `HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\GNU\GpgOL\disableAutoPreview = 1`
2. Restart outlook
3. Select an encrypted mail with e.g. security level 4 (Menüband: "Unsicher", which is expected)
{F27457515}
4. Open this mail (Menüband: "Sicherheit Stufe 4", Main: "Unsicher")
{F27457525}
5. Close this mail (Menüband: "Sicherheit Stufe 4")
{F27457531}
6. Select other encrypted mails with other security levels: the level is not updated accordingly (continues as long as encrypted mails are selected)
{F27457539}
{F27457564}
7. Unencrypted mails still update the level
{F27457544}