Slow wifi, packet loss, sometimes disconnect. RTL8822be driver, Ubuntu 16.04

I have (at least) one problem with my wifi on my Lenovo E480 Notebook running Ubuntu 16.04 with a Realtek b822 wireless card. I can't really pin down what the real problem is.

I observed the listed problems below. Sometimes together, sometimes alone. After reconnecting to the network they are sometimes solved, sometimes not:

• Most of the time really slow connection (0.1 Mbit/s compared to 100 Mbit/s with Ethernet)
• Using ping 8.8.8.8 I found out that I get a lot of packet loss. Sometimes it says 'Destination host unreachable' but I am still connected to the wifi.
• It's really unpredictable. It may work good for hours and suddenly decide to stop working. Or it works 5min before I need to reconnect again and again.

I'm mainly using my home network (WPA2) and the 'eduroam' network at university. The "Destination host unreachable"-problem seems to occur more in the university network. The wifi connection at home is always slow. (Just for the notebook, not for other devices.)

sudo lspci -v

05:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. Device b822
Subsystem: Lenovo Device b023
Flags: bus master, fast devsel, latency 0, IRQ 139
I/O ports at b000 [size=256]
Memory at f2100000 (64-bit, non-prefetchable) [size=64K]
Capabilities: [40] Power Management version 3
Capabilities: [50] MSI: Enable+ Count=1/1 Maskable- 64bit+
Capabilities: [70] Express Endpoint, MSI 00
Capabilities: [100] Advanced Error Reporting
Capabilities: [148] Device Serial Number 00-e0-4c-ff-fe-b8-22-01
Capabilities: [158] Latency Tolerance Reporting
Capabilities: [160] L1 PM Substates
Kernel driver in use: r8822be
Kernel modules: r8822be

The 'unassigned class' line seems suspicious..

sudo lshw

*-generic
            description: Wireless interface
            product: Realtek Semiconductor Co., Ltd.
            vendor: Realtek Semiconductor Co., Ltd.
            physical id: 0
            bus info: pci@0000:05:00.0
            logical name: wlp5s0
            version: 00
            serial: e8:2a:44:ff:bf:f9
            width: 64 bits
            clock: 33MHz
            capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
            configuration: broadcast=yes driver=r8822be driverversion=4.15.0-43-generic firmware=N/A ip=192.168.0.74 latency=0 link=yes multicast=yes wireless=IEEE 802.11
            resources: irq:139 ioport:b000(size=256) memory:f2100000-f210ffff

If you need more system information, please let me know. Thanks a lot!