PJSIP: Error reading CA certificates from buffer

Asterisk Asterisk SIP
1

Colleagues, after loading or rebooting, after calling from a sip client, I get this message.

[Dec 30 00:22:18] ERROR[100689]: pjproject: <?>:             ssl0x8306cea00 Error reading CA certificates from buffer

My transport is described as follows.

[transport-tls]
type=transport
protocol=tls
bind=0.0.0.0:5061
cert_file=/usr/local/etc/asterisk/LOCAL/certs/le-fc.pem
priv_key_file=/usr/local/etc/asterisk/LOCAL/certs/le.key
domain=my.domain.com
method=tlsv1_2
allow_reload=true

I use LetsEncrypt certificate, fullchain variant.
Of course, these are separate copies of certificates, the owner of which is asterisk:asterisk.

Colleagues, please tell me what this means? Did I configure something incorrectly or not completely?

Thank you for your answers,
Ogogon.