Bummer. Have you tested other apps listed under Standalone Programs on the Inkscape animation page such as Tupi and enve.
Unfortunately this is a big missing piece in the open source world right now. The best tool for open source motion graphics right now is probably Synfig, but it is not without issues. There is also a new option available since last year: Enve. Looking very promising, see: https://maurycyliebner.github.io/ . You can also have a look at OpenToonz, it was the animation tool used at Studio Ghibli, which has recently been open sourced. And in case you are interested, I'm also currently developing a new animation tool called "VGC Animation", although it's not going to be finished until a few years: https://www.vgc.io. I really hope the state of open source 2D animation software improves :)
i also think that blender is the best tool for such a job, but you might wanna look at the following project, which hasn't been around for long, but looks very promising: enve https://maurycyliebner.github.io/