A few members have noticed that the location of Petal was not updated on Vesselfinder website and also on club website on the right which uses the same service.

The reason being is what AIS actually is and how the online part of it works.

AIS works as a radio transmitter and it was not intended originally to be followed online on the internet. It’s not the original purpose. The way AIS is displayed on websites and apps is by receiving stations which are often volunteers that receive the signal at their seaside locations and upload it to the internet.
These stations are in random places alongside the coast and the AIS signal is in VHF band which is line of sight. It is therefore common for AIS signal to be lost around headlands and in certain harbours.
It also depends on the website, there are two main ones: Vesselfinder and Marinetraffic.
If vessel is lost on one, better check the other, link for Petal for an alternative website: https://www.marinetraffic.com/en/ais/home/shipid:7757367/zoom:14

That website shows Petal in Salcombe:

Petal in Salcombe and online AIS tips

Petal in Dartmouth: first two days

Petal in Falmouth