PJSIP Strange behavior

Hi!

I’ve recently faced with strange issue. FreePBX distro 10.13.66-16 with mostly default contexts.
I have PJSIP-Trunk and 188 PJSIP-Extensions and all worked just fine until I’ve added another one PJSIP-Extension.
Incoming calls to Trunk began to be sent back to the caller’s number, then came back, etc until the answer came busy.

All logs doubled many times
Part of the log of “one” call looked like this.

PJSIP/**-000000b6 is making progress passing it to PJSIP/-000000b5
PJSIP/**-000000b6 is making progress passing it to PJSIP/-000000b5
PJSIP/**-000000b6 is making progress passing it to PJSIP/-000000b5
PJSIP/**-000000b6 is making progress passing it to PJSIP/-000000b5
PJSIP/**-000000b6 is making progress passing it to PJSIP/-000000b5
PJSIP/**-000000b6 is making progress passing it to PJSIP/-000000b5
PJSIP/**-000000b6 is making progress passing it to PJSIP/-000000b5
PJSIP/**-000000b6 is making progress passing it to PJSIP/-000000b5
PJSIP/**-000000b6 is making progress passing it to PJSIP/-000000b5
PJSIP/**-000000b6 is making progress passing it to PJSIP/-000000b5
PJSIP/**-000000b6 is making progress passing it to PJSIP/-000000b5
PJSIP/**-000000b6 is making progress passing it to PJSIP/-000000b5
PJSIP/**-000000b6 is making progress passing it to PJSIP/-000000b5
PJSIP/**-000000b6 is making progress passing it to PJSIP/-000000b5
PJSIP/**-000000b6 is making progress passing it to PJSIP/-000000b5

Then I deleted some extensions and everything was fine again. I started to add extensions one-by-one and when I reached the number of 190 PJSIP contacts at all(extensions+1 Trunk) - the same issue appeard.

Finally I’ve noticed that my Trunk had context “from-internal”, and changed it to “from-trunk”, and all calls became fine with any number of PJSIP contacts.

But why this issue appeared only when I reached 190 number of contacts? Is it bug?