Calendar event descriptions adding characters

[nbwork]

My husbands calendar events have extensive event descriptions (where he keeps notes on different clients, etc). Many events are getting "\n" and "&nbsp" added to every line, or every time there is punctuation in the descriptions, and the number of "" seem to grow.

He is using his Etesync calendar with his GrapheneOS phone and Simple Calendar, and on his Linux Mint desktop with Thunderbird. I also sync it to my phone the same way and to my Windows PC with EmClient. Trying to isolate now if one device is causing the problem.

For example:

.Infected?&nbsp\\\; Bad update?&nbsp\\\; Win Vista.&nbsp\\\;&nbsp\\\; 9.12.13
\\n
.Replace cable modem.&nbsp\\\; Checkup
\\n
.&nbsp\\\; 8.29.14

[nbwork]

I see those are html tags - every time there is a space, it puts in   Then it keeps adding more back slashes This is a calendar that was originally exported from Outlook in a .ics file.

[nbwork]

I think it was eMClient adding the html tags. It shows them, rather, and then if you open an affected event in emclient and edit it, then other clients like Simple Calendar or Thunderbird see the tags. We have taken emclient out of the mix, and things seem to be workings so far.