Upgrade postfix-2.7.4 to postfix-2.8.7 breaks sasl2 smtp

[AA6QN]

I use sasl2 for smtp delivery to a remote mail relay. works fine with postfix-2.7.4

/etc/sasl2/smtp.conf
pwcheck_method:saslauthd
mech_list: plain login

/etc/postfix/main.cf (smtp related)
# Outgoing
smtp_sasl_auth_enable = yes
smtp_sasl_security_options =
smtp_sasl_password_maps = hash:/etc/postfix/saslpass

I upgraded to postfix-2.8.7 keeping my postfix and sasl configuration files unchanged.

Incoming smtpd worked fine.

I was getting these logwatch errors for outgoing smtp:
SASL authentication failed; cannot authenticate to server (my-remote.smtp-gateway)[X.X.X.X]: no mechanism available

I tried both stable and latest versions of cyrus-sasl with the same results

Falling back to postfix-2.7.4 and the outgoing mail delivery started working again.

According to the NVD database 2.7.4 looks good for now.

Anyone else seen this?