Dictionaries lose entries?

Hello,
Every couple of months I reset my phone, which means I have to reinstall Pleco.

I thought I was pretty used to the reinstalling process, as I periodically save:
- my flashcards
- my User dictionary

However this time I realize many of my flashcards lost the dictionary definition. It's not a remap problem, the entry is really missing from the dictionary. I don't know in detail which dictionary it was, but it must be one of the following: PLC, CC, UNI or ADS, which I always have and always download from the add-on tab.

Examples of definitions that I had, I am certain that they came from those dictionaries, and they are now missing.
盡忠職守 ～fulfill one's duty
古龍水 ~ cologne perfume
戒賭 ~ trying to stop one's addiction at gambling
上鐘 ~ to clock in for work

The last one, I added yesterday morning, just before doing the phone reset. In the evening, when practicing flashcards, I noticed it had the "missing entry" text thing.

Question: is it normal that the dictionaries mentioned above remove some entries? If so, should I spend time backing those dictionaries up as well, even though they are free and available through the Add-ons tab?

Thanks~

It hurts a lot to lose content, I have around 10k flashcards and it looks like 2-3% of them now have missing entries. For most cases I remember it and I will fill-in the definition when I see it's missing, but I would really like to feel safe that all my stuff always remain...
Maybe a new feature like "backup all"? [saving flashcards, all dictionaries and all my pleco configuration i.e. traditional/simplified, show 注音 etc]

The first three of those are covered by our free CC-Canto add-on dictionary; perhaps that's the one that you're missing. You can download that in Add-ons / Dictionaries / All Free (you'll also see a prompt to download it automatically if you enable Cantonese support).

We don't yet have support for automatically re-downloading free dictionaries, only paid ones; until recently our most popular two free add-on Chinese-to-something dictionaries were Adso and HanDeDict, and since both of those dump their text directly to the flashcard database rather than linking to entries (due to the impossibility of mapping their entry IDs between versions) this didn't really come up, but now between CC-Canto and the MoE dictionaries it's probably worth adding a facility for that.

Thanks Mike. I installed the Cantonese one, hopefully it will cover some of the missing words, like the first 3 in my examples above.
I am still wondering what can be the reason why those words disappeared. I suppose dictionaries evolve and some words can be removed, but if those words made sense why were they removed?...
Do you recommend any Paid dictionaries, for reading novels or watching movies, mostly modern and general vocabulary? If they make a good difference I am up for trying that!

I don't think they did disappear, I think they just linked to a dictionary you hadn't downloaded yet.

Our ABC and KEY add-on dictionaries cover a lot of Chinese words that aren't in the built-in ones, if you're looking to expand your Chinese vocabulary coverage.