A change of that small an amount in the display reading may not reflect an increase in pressure.
I was told to ignore anything in the tens and units places on pressure gauges and computer displays because gauges can meet standards being off by five or ten percent.
This note from the SPG page at
Dive Gear Express describes the EU standard:
SPG manufacturers all seem to reference the EN250 SCUBA equipment standards from the European Union for their accuracy specification of these devices. The EN250:2014 standard states "the accuracy of any indicator tested at the following fixed decreasing pressures shall be: ±15 bar at 300 bar; ±10 bar at 200 bar; ±10 bar at 100 bar; ±5 bar at 50 bar." The imperial units equivalent for this standard would be approximately: ±218 psi at 4351 psi; ±145 psi at 2901 psi; ±145 psi at 1450 psi; ±73 psi at 725 psi. In terms of a percentage, from about ±5% in the middle range to ±10% in the low range of the scale.
Also, if you switched regs because the tank associated with the first reg was getting low, you may be dealing with the fact that gauges can be less accurate that the low end of the pressure ranges they measure. Again, the pressure may not be increasing. Another note from the same web page:
The nature of all mechanical pressure gauges is they are most accurate in the middle of the scale and least accurate at the ends of the scale. Even when perfectly calibrated in the mid-range, in our experience all mechanical SCUBA SPGs have extremely poor accuracy at the very low end of the scale; possibly indicating significantly more (or less) breathing gas than what is really in the tank. That is why divemasters are often heard to say "Be back on the boat with 500 psi." Just to be clear, this is not a reflection on the quality of the gauge but rather a limitation of the mechanical Bourdon tube technology at the very low end of the gauge range.
I do not know if either of these issues apply to AI transmitters, but "significant digit over-run" may be an issue.