Thank you very much for sharing the crucial information that you were using USB2AX when you used MANAGER to connect to your XM-430. In short, via this test, we now know for sure that your XM-430 works fine.
Going back to the OpenRB-150, so far your results showed that Serial works fine as you could download your Arduino sketch and all your Serial.println() commands worked fine.
But any time that you wanted to communicate with your DXL via Serial1, this is when/where you are getting problems. Right now, we don’t know if the issue is with Serial1 per se or with the TTL Communication Circuitry (Half-Duplex) that comes after it (XM430-W350-T/R). So my recommendation is to start an RMA process with the ROBOTIS dealer where you purchased the OpenRB-150 from, if your product is still under warranty.
Regarding using Serial3, this person had a similar issue with Serial1 on an OpenRB-150 and decided to dispense with using the Half-Duplex circuitry together and so he/she used Tx and Rx of Serial3 directly - see this post (it is in Korean so you’ll need to turn on Translation Service on your web browser).
So you can try this solution too - if you cannot wait for the RMA process, but make sure to use a Logic Level Shifter such as this one from Pololu - for a better long-term result:
As TX/RX from the OpenRB-150 on Pins 13-14 operate at 3.3V while the DATA Line for the DXL would kick back at 5V.
UPDATE: 4/2/2023
@jduv
As I have not yet (myself) checked out that previously posted method of using Serial3 and connecting Tx+Rx together to the DATA line of the DXLs, without the Logic Level Shifter, so I got myself a similar setup as shown below - whereas I used the OpenRB-150 DXL connector to only power the DXLs (this special RED DXL cable has its DATA line severed) and I connected Pins 13 and 14 together to the DATA Line of the WHITE DXL cable which has its VDD line cut-off. Both cables are connected to the same GROUND as the OpenRB-150.
But all I could do was reading Present Positions, all my Goal Position commands did not seem to go through. It looks like that, for my system, I cannot reproduce the results claimed in that previous post.
So it looks like that you may have to go through the RMA process to let the ROBOTIS folks to look for what is really going on with your OpenRB-150.
2nd UPDATE: 4/2/2023
@jduv You are not alone anymore in getting these “strange” issues on your Open-150, because I just got the same symptoms on the Open-150 that I had been using trying to help you. It was working for more than a year now so my warranty is gone. I will contact @ROBOTISUSA separately for this.
Essentially for now, I can download any code on my OpenRB-150, and it will download with no errors OK, but my code does nothing when you look at the Arduino Serial Monitor (COM14) at run time (see picture below). However I can hook up my U2D2 at the same time to these DXLs via Dynamixel Wizard (COM15) and I can see and operate my DXLs as normal! . Basically my OpenRB-150 now has become a glorified power source for my DXLs - that is all 
My hunch is that the TTL Communications Circuitry somehow gave out, but Serial1 is still working.