crldp support for ftp uri

Hello,

i have a question regarding ftp support in crldp field of the certificate.

I can access the ftp from the F5:

[root@:Active:Standalone] config # curl ftp://a.b.c.d/xxx.crl > crl

 % Total  % Received % Xferd Average Speed  Time  Time   Time Current

                 Dload Upload  Total  Spent  Left Speed

100  669 100  669  0   0 25225   0 --:--:-- --:--:-- --:--:-- 29086

The file that got downloaded is valid crl file that contains all information. The same uri is located in certificate field of crl distribution point. Because LTM does not support HTTP i have APM that works fine when it comes to HTTP uri. I tried to do the same according to this article:

https://support.f5.com/csp/article/K12975

Article says FTP uri is allowed so i assume F5 should accept it. However it does not. APM returns the error that says:

May 20 15:17:55 warning apmd[25146]: 0149015e:4: (null):Common:b3d2e3e7: CRLDP Auth agent: CRL lookup failed for LDAP url 'ftp://a.b.c.d/xxx.crl ' reason 'Invalid CRLDP URL'

Is it even doable? Anyone got idea?