Yep, just like this.
That should get them going in a cycle

Dummy job
In Condition - ()
Outcondition - A +

Job A
in Condition - A
Out condition - B + and A -

Job B
In condition - B
Out Condition - C + and B -

Job C
In Condition - C
Out condition A+ and C-

The Dummy job is what adds the in condition for the first run of JOBA.
That is what will initiate the cycle.

Dummy [A_in + ]->
JOBA -[A_in -] & [B_in +] ->
JOBB [B_in -] & [C_in +] ->
JOBC [C_in -] & [A_in +] ->
JOBA -[A_in -] & [B_in +] ->
JOBB [B_in -] & [C_in +] ->

I'd create a Dummy job to kick off the Cycle by adding JOBA's in condition, Then when JOBA finishes it deletes it's own in conditon & adds the in condition for JOBB, the cycle runs through & then JOBC kicks off JOBA Dummy [A_in + ]-> JOBA -[A_in -] & [B_in +] -> JOBB [B_in -] & [C_in +] -> JOBC [C_i...

I had a similar issue after we upgraded to AFT V7.
We resolved it by changing the Time Limit to 2 minutes (after trying various other options, we discovered that this was the shortest time that would still work).

I would try that first.

Good luck