Yes, it does that. It has been doing that for more than a month, and I have not updated the software or done anything to change how it works.
For example, after having succeeded, as reported here earlier, with much fiddling, to get the font size right, now when I paste some text copied from somewhere else and then continue typing, the new text comes out in the size of the font of the pasted bit.
More than that: if the pasted bit letters are in a different color (say red, instead of black) what I type afterwards comes out in red. And if the pasted bit has also a color background, let’s say yellow, then everything I type after that comes on a yellow background.
It does not matter if I continue typing right after the pasted bit, or I leave a double space, or insert a blank line. It is relentless.
This happened last week, when I emailed someone asking questions about a new contract I had to sign and he answered placing his replies next to my questions, in red on a yellow background.
T-Bird: the interesting email client that makes life interesting.
(Did I tell you how much I hate T-Bird?)
Ex-Windows user (Win. 98, XP, 7); since mid-2017 using also macOS. Presently on Monterey 12.15 & sometimes running also Linux (Mint).
MacBook Pro circa mid-2015, 15" display, with 16GB 1600 GHz DDR3 RAM, 1 TB SSD, a Haswell architecture Intel CPU with 4 Cores and 8 Threads model i7-4870HQ @ 2.50GHz.
Intel Iris Pro GPU with Built-in Bus, VRAM 1.5 GB, Display 2880 x 1800 Retina, 24-Bit color.
macOS Monterey; browsers: Waterfox "Current", Vivaldi and (now and then) Chrome; security apps. Intego AV