GRE tunnel: system link-monitor update-cascade-interface does not work

Hello,

It seems that the link monitor "update-cascade-interface" does not work with GRE interface: when the status is link monitor is "die", the source interface (GRE) remains up.

Extract from documentation:

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update-cascade-interface {disable | enable} Enable to bring down the source interface if the link health monitor fails. Disable to keep the interface up if the link health monitor fails. Default is enable.

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Has somebody already seen this situation ?

Thanks in advance for your help.