What if the property manager made mistakes?

It could be anything... a mistake in estimating, a cost overrun, or something like the place burns down and the insurance wasn't properly taken out, or theft (of the money outright) or theft of materials along the way.    

Are there any common mistakes new investors make when working with brokers, lenders, or contractors?

The common mistake here is that not ALL your equity is borrowable on a property and even more so on a investment property then an owner occupied property. 

In our experience, the #1 mistake landlords make when selecting a Property Management Company (PMC) is ASSUMING instead of CONFIRMING.

.: I just hired an architect to design and plans submit for ADU in my 8 multi unit to use the tuck under parking.Some people say do not try to be the general contractor as it will take way more time, costly mistakes and will be nearly impossible to manage with current work. best to hire a company that will do it all and cost about $250 per square foot.

Make no mistake it isn’t quick or especially comfortable but it can definitely be profitable.As for the rent a room thing in most locales I have to wonder if the additional rent is worth the hassles of dealing with the increased time and liability of multiple tenants in one property but that’s a totally different conversation. 

You learn over time how this works or sometimes a mentor is the right choice to get there faster with less expense and fewer mistakes. 

I can totally understand they were overworked and understaffed, and as a result, mistakes were made.

With fewer buyers in the market due to high rates, investors who move now have leverage to negotiate on purchase price, seller credits, and even off-market deals.The biggest mistake investors can make right now is waiting for perfect conditions.