Sodick BF275 - McWilliams 812 Mark X Gold Control Cutting 5" Brake Die/Prehard

Yes, I know this is an old machine, but it's all we have and does not run a lot. We are making some in-house tooling that requires a 5" tall cut, which is a lot for this machine. The configuration of the parts are ideal for Wire EDM. We are having so much inconsistency in cut speed and wire breakage. We have found ways to keep it going, but the speed is so slow that it is almost impractical. We will average .030 a minute for an entire part, put the next block in and never get over .008 a minute. As a trial, we ran a part in annealed A-2, just because we had some. The machine was consistent. Ran 2/3 of the part at around .022 until the wire spool was changed, then we were back to the low speeds again. The water resistivity is at 5. The flushing is good. This is not a high precision part, just complex shape not ideal for milling.
Contacts are changed. Table is isolated.
What are we missing?