The Telegraph wrote a useful article about AGMs and voting. see https://www.telegraph.co.uk/investing/shares/use-broker-hold-investments-account/
It was headed
How to use your broker to hold your investments to account
But the real story was in the byline – Stockbrokers require investors to jump through lots of hoops to register their vote.
It also explained the problems and quoted ShareSoc:
However, new investors might not know that owning company shares comes with part ownership of a company – and with it the right to vote on issues at their annual general meetings, or AGMs.
Investors can make their voice heard on far-ranging topics, from how much company leadership gets paid, to whether it pays a dividend or donates to a political party.
But fewer than 1pc of people actually take up their votes, according to ShareSoc, a non-profit organisation which represents the interests of shareholders in Britain.
Cliff Weight, of ShareSoc, said this was due to stockbrokers making it challenging for DIY investors to use their vote. Each broker has a different process for submitting votes.
The Telegraph article also included its guide on how to navigate the different broker processes.
More Information on Platform comparisons is in the ShareSoc Forum https://www.sharesoc.org/forums/topic/shareholder-rights/
Cliff Weight, Director, ShareSoc