Hello,
Please check the speed of the interfaces that are affected here as detected by iMC, via their Device Details -> Interface List -> open the affected interface (like Ten-GigabitEthernet1/0/51). Is the Speed (bps) shown as 10G, or something else?
Based on the alarm, it sounds like iMC is not detecting the interface bandwidth correctly, as it claims the "800Mbps" threshold is exceeded, which would be the default Threshold 2 for 1G interfaces, and not 10G.
For interface-specific indexes like the "Interface Receiving Rate" you showed, the alarm thresholds are variable depending on the speed detected for each interface - so a 1G interface would have a different alarm threshold than a 10G interface and so on.
If you use aggregations and thus have other speeds like 2G, 20G etc., you would have to manually define thresholds for alarming. This can be done via Performance Management -> Global Index Settings -> expand the interface index to modify, select the gear icon under Operation column, and select Modify Index. A window will appear like the following, where you can manually adjust each of the separate interface speeds and their thresholds:

If the interface speed is detected incorrectly by iMC, you can check whether it's an iMC or device issue by polling the device's standard interface table via SNMP (for example using IMC's MIB Management tool), and looking at what speed is reported for the interface having issues.
Name: ifTable
Type: OBJECT-TYPE
OID: 1.3.6.1.2.1.2.2
Full Path: iso.org.dod.internet.mgmt.mib-2.interfaces.ifTable
Module: RFC1213-MIB
Parent: interfaces
Max Access: not-accessible
ComposedSyntax: SEQUENCE OF IfEntry
Status: mandatory
Description: A list of interface entries. The number of entries is given by the value of ifNumber.
Using MIB Management, you could right-click on ifTable and select Table View. This will show you all the values for the interfaces that the device reports in a nice table view, including the speed:
IMC should use whatever value the device provides for interface speed as reported above, so if this table shows an incorrect speed value for the interface, it's an issue on the device side.
Hope that helps.