Disparity between Solis inverter Import/Export and smart meter Import/Export

[Slateral]

The difference between the Import and Export readings of my Solis inverter and my smart meter readings, according to Octopus, seem excessive, particularly the import readings in the summer months.

Has anyone else had similar disparities? Is this normal? I understand that smart meters are calibrated and inverters are not, but the difference seems excessive.

2023​	Inverter Import	Octopus Import	%ge Difference	Inverter Export	Octopus Export	%ge Difference
January	528	597.6	13%	14	17	21%
February	430	505.4	18%	65	68	5%
March	530	608.5	15%	36	45	25%
April	216	272.4	26%	205	219	7%
May	173	228.8	32%	262	280	7%
June	102	145.2	42%	380	402	6%
July	168	230.5	37%	173	187	8%
August	148	203.1	37%	203	220	8%
September	152	199.4	31%	213	220	3%

 

[ExArmy]

the inverter will be measuring current using a CT clip that probably cost pennies to make in China, they are not that accurate at the best of times.
I connected 2 CT's (from AC battery and EV chargepoint) to measure solar generation and got 20% difference between the two