Keys in Pageant (0.76) are ignored by WinSCP after upgrade to 5.19.6, worked before this version.

Since upgrading to WinSCP 5.19.6 my keys in Pageant are ignored. PuTTY can still use them. This only happened after upgrading WinSCP. It worked before my upgrade.

What version were you using previously?
Are you sure it broke with WinSCP upgrade?
Wasn't it rather a server upgrade?
You might need WinSCP 5.20.x (RC) for:
Issue 1952 – Support rsa-sha2-256 and rsa-sha2-512 SSH public key algorithms