Well, I don’t know what to say about what is going on…it is possibly user error and I don’t say that to be critical…I’m working through some of the same things as I get my Tascam prototype console setup…plenty of “oh duh” moments. It shouldn’t matter with that patchbay and the 388 if you use TS or TRS snakes, the critical thing is the SEND jacks connect to the top row of patchbay jacks in the back, the RCV jacks connect to the bottom row in the back, and each patchbay jack set must be configured normalling or half-normal. If setup that way the 388 should work just like you have nothing plugged into the SEND/RCV jacks. Now, there is one caveat…if you haven’t used the insert points on the 388 very much and depending on the conditions in which it’s been used and/or stored during its life there could be some oxidation on the contacts in the SEND/RCV jacks. And this will manifest as intermittent connections that seem inconsistent. I know people berate the RCA jacks on the old Tascam stuff and others, but honestly they tend to perform more reliably at age compared to the TS jacks because of the way the contacts mate to the plug…there’s something of a more positive mating with the RCA jacks. The down-side to the RCA jacks, at least those that are PCB mounted to phenolic boards is compromised solder joints. So I find sometimes with the RCA jack PCBs I have to re-flow solder joints, but the jacks themselves work better even when visibly oxidized, and with the TS jacks they need a bunch of exercising, maybe some clearing with canned air, and even a little spritz of DeoxIT D5. Maybe try some of that and see if it helps. I just dealt with this with a Tascam PB-32R patchbay…it’s really clean and nice on the outside and I assumed it would be fine, but there was no end to the futzing with the jacks…I cut my losses and swapped in one of my Neutrik NYS-SPP-L TRS patchbays…16 more points, easier to configure, glass fiber PCB material for the jack sets…tight positive contact jacks. Problem solved. This is not your problem as far as at the patchbay end, but you might be struggling with the same issue but at the machine end.