RS485 to TTL - Difference in two visually identical devices

Hardware
1

Doing my Delta Solivia Inverter ESPHome modbus integration, I experienced a really strange issue with the actual RS485 module hardware.

I have two different versions ‘on stock’ of the visually, completely identical ttl (3,3v/5v) to rs485 module.The Dollatek version (marked with RS485 to TTL on the pcb) bought on Amazon and the ‘no name’ version (marked with XY-017 on the pcb) bought on AliExpress.

The Dollatek version works perfectly with all my connected hardware, Schneider iEM3155 Energy Meter, Delta inverter & Nilan air vent system. But the XY-017 version somehow shorts/overloads the esp8266 when I use it with the Delta Inverter. Perhaps the XY-017 version draws a bit more power than the other version (3,3v feeded from the esp8266 pin) ? Everything works flawlessly with the other device type ? I thought that I might just experience one erroneous device. But no, I tried three devices and none of them worked with the inverter. But all three worked with my Energy Meter ?

Devices looks completely identical, populated components also seems to be identical. But apparently there’s a difference somewhere. Could anyone explain or have experienced similar ?
If not, let this be a gentle warning to exercise caution when choosing RS485 modules.

No name version - Marked XY-017 on the pcb backside:

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Dollatek version - Marked RS485 to TTL on the pcb backside:
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Regards
Henning

2

No specific answer to your question. I do notice that the XY-017 has several extra via’s to VCC and GND, which presumably go to the bottom layer and then elsewhere.

I guess you don’t have a separate external power supply that you could to power the converter? You would still tie all grounds together (ESP, this, and ext power supply), but the external supply would only be connected to this board. Having said that, I’d be surprised if this board was pushing your normal ESP supply over the edge.